Proto-Indo-European verbs

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The verbal system of the Proto-Indo-European language (PIE) was a complex system, with verbs categorized according to their aspect — stative, imperfective, or perfective. The system utilized multiple grammatical moods and voices, with verbs being conjugated according to person, number and tense. The system of adding affixes to the base form of a verb (its root) allowed modifications so that it could form nouns, verbs, or adjectives. The verbal system is clearly represented in Ancient Greek and Vedic Sanskrit, which closely correspond in nearly all aspects of their verbal systems and are two of the most well-understood of the early daughter languages of Proto-Indo-European. Aside from the addition of affixes, vowels in the word could be modified in a process called ablaut. This is still visible in the Germanic languages (among others)—for example, the vowel in the English verb to sing varies according to the conjugation of the verb: sing, sang, and sung.

The system described here is known as the "Cowgill-Rix" system and, strictly speaking, applies only to what Don Ringe terms "Western Indo-European" (Western IE), i.e. IE excluding Tocharian and especially Anatolian. The system also describes Tocharian fairly well, but encounters significant difficulties when applied to Hittite and the other Anatolian languages. In particular, despite the fact that the Anatolian languages are the earliest-attested IE languages, much of the complexity of the Cowgill-Rix system is absent from them. In addition, contrary to the situation with other languages with relatively simple verbal systems, such as Germanic, there is little or no evidence of the "missing" forms having ever existed. Furthermore, many of the forms that do exist have a significantly different meaning from elsewhere. For example, the PIE perfect/stative conjugation shows up simply as a present-tense conjugation known as the ḫi-present, with no clear meaning; on the other hand, the PIE nu-present, which in other languages is a primary verb suffix with no clear meaning, is in Hittite a productive secondary verb suffix that forms causative verbs. (On the other hand, Germanic, among others, has a class of present-tense verbs derived from PIE perfect/stative verbs, and both Germanic and Balto-Slavic have a class of secondary n- verbs with a clear meaning, derived originally from nu- and/or neH- verbs, so it is possible that many of the Anatolian differences are innovations.) It is generally accepted that the Anatolian languages diverged from other IE languages at a point somewhat before the Cowgill-Rix system was fully formed; however, there is no consensus concerning what the inherited system looked like, and which Anatolian differences are innovations vs. archaisms.


All of the older Indo-European languages show a complex system of verb conjugation, with verbs conjugated across multiple categories. In general, the traditional Cowgill-Rix system reconstructs the following categories for Proto-Indo-European (excluding Hittite and other Anatolian languages):

  • Person: 1st, 2nd, 3rd
  • Number: singular, dual, plural
  • Voice: active, mediopassive (or "middle")
  • Mood: indicative, subjunctive, optative, imperative, possibly also injunctive (used for "gnomic" statements expressing general truths or unchanging facts)
  • Aspect: imperfective ("present"), perfective ("aorist"), stative ("perfect")
  • Tense: present, past ("imperfect")

Some of these categories (e.g. the dual) tended to drop out in time, while some languages innovated new categories (e.g. the future tense).

The original interpretation of the tense and aspect categories has been a thorny issue; see below. The traditional names follow the usages of these forms in Ancient Greek, where the imperfect generally indicates an ongoing or repeated past action, the aorist a single past action viewed in its entirety, and the perfect as a past action with present relevance. They are sometimes compared, respectively, with the English forms "I was doing, I did, I have done", or (even more accurately) the Spanish forms "(yo) hacía, hice, he hecho". However, the meaning of these forms is somewhat different in Sanskrit, and even in Ancient Greek the canonical meanings only apply in finite verbs in the indicative mood; the categories of present, aorist and perfect also exist in other moods and in participles and infinitives but in these cases have only aspectual values.

Verbs could be formed according to multiple conjugations, each with its own way of constructing a given category. In the most conservative languages (e.g. Ancient Greek, Sanskrit, Tocharian, Old Irish), there is a separate set of conjugational classes for each of the tense/aspect categories, with no general relationship obtaining between the class of a given verb in one category relative to another. The result is that verbs must be described by a set of principal parts, each listing the method of forming a given category in that verb. There was a gradual tendency to regularize this system into a single set of global conjugations, which was partly complete in Latin (although not in Class III, the -ere verbs), and mostly complete in Germanic. Conversely, the oldest stages of the most conservative languages (esp. Vedic Sanskrit) reveal clear remains of an even less organized system, where a given verb root might have multiple ways, or no way at all, of being conjugated in a given tense/aspect category — sometimes with meanings that differ in unpredictable ways. This clearly suggests that the tense/aspect categories originated as separate lexical verbs, part of a system of derivational morphology (compare the related verbs "to rise" and "to raise", or the abstract nouns "produce", "product", "production" derived from the verb "to produce"), and only gradually became integrated into a coherent system of inflectional morphology, which was still incomplete at the time of the proto-language.

There were also a number of secondary formations, e.g. causative ("I had someone do something"), iterative/inceptive ("I did something repeatedly"/"I began to do something"), desiderative ("I want to do something"), which are distinguished from the "primary" formations by the fact that they generally are part of the derivational rather than inflectional morphology system in the daughter languages — although, as mentioned above, there was no clear boundary between the derivational and inflectional system of verbs in PIE. Not surprisingly, some of these formations have become part of the inflectional system in particular daughter languages. Probably the most common example is the future tense, which exists in many daughter languages but in forms that are not cognate, and tend to reflect either the PIE subjunctive or a PIE desiderative formation.

The methods of forming a given verb class in a given category are also complex and variable. In general, a given verb form can be described as a combination of three parts: ROOT/ABLAUT — SUFFIX — ENDING. The first two parts together (ROOT/ABLAUT — SUFFIX) are known as the stem. The ending generally indicates person, number and voice, while the stem generally indicates the verb class and category (i.e. mood and tense/aspect). A given class/category combination usually forms its stem using a combination of three types of root modifications:

  • Adding a suffix.
  • Changing the ablaut of the root. The ablaut is the type of vowel used in the verb root: generally, either e, o, ē, or no vowel (the "zero grade"). For some class/category combinations (particularly the "athematic" types; see below), there is also ablaut variation within a given paradigm. The most common case is for a "stronger" variant to be used in the active singular, while a "weaker" variant is used elsewhere in the paradigm. Examples of such ablaut variations are e or o vs. no vowel, and ē vs. e (so-called Narten classes).
  • Changing the position of the stress, usually either on the root or suffix. Zero-grade ablaut roots are generally unstressed (i.e. the stress is on the suffix), while the other grades are generally stressed; but, naturally, with some exceptions.

In addition, some verb classes use additional types of root modification:

  • The n-infix type of present class inserts an n within the root, before the last consonant.
  • A number of different classes have reduplication, i.e. an additional syllable is prefixed onto the root, consisting of a copy of the first root consonant followed by a vowel e or i.

Note that this means that a given verbal category might form its stem in one of many quite different ways, sometimes with different endings. In addition, sometimes the identical stem formation is used across different class/category combinations. For example, the PIE aorist is usually formed in one of the following ways:

  • The root aorist, which adds athematic endings directly onto the root, with e/zero ablaut within the paradigm: e.g. *leykʷ-t "he left" from root *leykʷ.
  • The sigmatic aorist, which uses a suffix -s along with athematic endings and ē/e ablaut within the paradigm: e.g. *dēyḱ-s-t "he pointed out" from root *deyḱ.
  • The reduplicated aorist, which uses reduplication along with athematic endings and e/zero ablaut within the paradigm.
  • The thematic aorist, which adds thematic endings onto the root, with no ablaut within the paradigm: e.g. *h₁ludh-et "he went" from root *h₁lewdh, with zero-grade ablaut.

All four methods of forming the stem are also found in the present, although sometimes with different ablaut. Although the present and aorist use different endings, the imperfect is formed using the present stem and the same endings as in the aorist; as a result, present and aorist stems are generally formed in different ways, to avoid ambiguity.

As just indicated, there are multiple sets of endings, depending on both the class and category, and in some cases distinct endings may be the only thing distinguishing one category from another. Endings are characterized as primary vs. secondary, and as thematic vs. athematic. Primary endings are generally used in the present indicative and throughout the subjunctive, while secondary endings are used elsewhere. In many cases, the primary endings are distinguished relative to the secondary endings by an additional suffix (originally -i in the active and -r in the mediopassive, although the majority of subfamilies generalized -i to the mediopassive as well). Athematic endings are added directly onto the stem, while thematic endings are usually the same as the athematic endings but with an additional "theme vowel" (either e or o) added between stem and ending. There are also some unpredictable variations among different sets of endings, e.g. first singular active athematic *-mi but thematic *-oh₂. Finally, there is an additional set of endings specific to the perfect, and another set specific to the imperative.

Verbal categories

Proto-Indo-European verb lexemes belonged to one of two aspect classes: stative (verbs that depict a state of being; also known as the perfect system) and eventive, the latter of which is broken down into imperfective (verbs depicting ongoing, habitual or repeated action; also known as the present system) and perfective (verbs depicting a completed action or actions viewed as an entire process; also known as the aorist system).

The terminology around the stative, perfective and imperfective aspects can be confusing. The use of these terms here is based on the reconstructed meanings of the corresponding forms in PIE and the terms used broadly in linguistics to refer to aspects with these meanings. In traditional PIE terminology, the forms described here as stative, perfective and imperfective are known as the perfect, aorist and present systems. The present/imperfective system in turn can be conjugated in two tenses, described here as present and past but traditionally known as present and imperfect. The traditional terms are based on the names of the corresponding forms in Ancient Greek (also applied to Sanskrit), and are still commonly encountered. Furthermore, there is a separate secondary-verb form commonly known as the "stative" and marked by a suffix *-eh₁-, which has no connection with the stative/perfect described here.

The following table shows the two systems of terminology.

Process Aspect Aspect (traditional name) Tense Tense (traditional name)
Stative Stative Perfect system (unmarked) Perfect tense
Eventive Perfective Aorist system (unmarked) Aorist tense
Imperfective Present system Present Present tense
Past Imperfect tense

From any particular root, verbs could be derived in a variety of means. Basic verbs typically used the root itself as the stem (parallel to the "root nouns"), but many verbs were formed by adding another suffix to the root. Roots generally had their own "inherent" aspect, which determined the aspect of a basic verb. Each verbal lexeme, especially eventive verbs, took on its own "root aspect", ostensibly according to the semantics of the root, although there are numerous unexplained surprises. Thus, there were verbal roots whose default meaning was durative, ongoing, or iterative, and verbs derived from them were generally imperfective in aspect. Roots whose meaning was punctiliar or discrete created perfective-aspect verbs.

A verb needed no derivational markers when functioning within its own root aspect. Affixes of various types were used to switch the inherent aspect to a different type. Examples of aspect switching affixes include -yé-, -ské-, and the nasal infix, all of which were used to derive imperfective verbs from roots whose inherent aspect was not already imperfective. Conversely, the "s-aorist" formation (retained most notably in Greek) used the suffix -s- to create perfective verbs. Many roots were "hyper-characterized", however, with an aspect marker added to a root that already had the correct aspect. This may have been done in order to emphasize their root aspects. For example, the s-aorist also seemed to have been used when the verb root was inherently perfective already.

The Indo-European verb was not necessarily conjugated with one possible affix. Several aspect switchers were available to be added to the root, particular markers were not exclusively assigned to any root. Certain roots did show a preference for the same markers in multiple daughter languages, but the use of a particular marker was not exclusive, and a variety of formations are often found for the same root. For example, the basic root for "stand", *steh₂-, was a perfective root. Therefore, the word in its default aspect had the punctual sense of "come to a standing position; to rise from a sitting position". In order to speak about "standing" in a present, durative sense ("be in a standing position"), the root aorist required a derivational marker to put it into the imperfective aspect. For this root, the imperfective aspect switcher was often reduplication (cf. Greek ἵστημι, Sankskrit tíṣṭhati), but the Germanic languages also show a nasal infix or suffix for this root (Gothic present ik standa vs. preterite ik stōþ), at least by a later period. The Slavic languages, meanwhile, also have a form derived with the -yé- suffix.

Conversely, a verb did not necessarily have forms for all three aspects. There were many roots that seem to have had forms only for one or two aspects. For example, the root *h₁es- ("to be") seems to have formed only an imperfective verb, no perfective or stative forms can be reconstructed. Various later languages amended this situation differently as needed, often by using entirely different roots (suppletion). Latin used the root *bʰuH- ("to become") as the perfective aspect of *h₁es-, while the Germanic languages used the root *wes- ("to live, to reside") in that role. This situation suggests that in the earliest Proto-Indo-European, the various aspect stems were still very much independent verbs in their own right, and came to be used as single paradigms only later.

In the indicative mood an imperfective verb was conjugated in two tenses: present and past. If the perfect developed before the end of the common PIE period, it was near the end. Verbs had at least four moods: indicative, imperative, subjunctive and optative, as well as possibly the injunctive, reconstructible from Vedic Sanskrit and Homeric; two voices: active and mediopassive; three persons: first, second, and third; and three numbers: singular, dual, and plural. Verbs were also marked by a highly developed system of participles, one for each combination of tense and mood, and an assorted array of verbal nouns and adjectival formations.



The stative aspect signified a current state of being. It was traditionally known as perfect, a name which was assigned based upon the Latin tense before the stative nature of the Proto-Indo-European (PIE) form was fully known. While Latin conflated the concept with tense, in PIE there was no association with any particular tense. The stative aspect was marked formally with its own personal endings, which differed from the eventives by a root in the singular in o-grade, but elsewhere in zero-grade, and typically by reduplication.

In many daughter languages, the stative took on a meaning that implied a previous action that had caused the current state, a meaning which resulted in the Greek perfect. Eventually, by shifting emphasis to the inchoative action, an action that was just started or a state that was just begun prior to the resulting state, the stative generally developed into a past tense (as in Germanic, Latin, and later, Greek). The original present sense of the IE stative is seen in the Germanic preterite-present verbs such as Gothic wait "I know" (< PIE *woidh₂e, originally "I am in a state resulting from having seen/found"; cf. Latin vidēre "to see", Sanskrit vinátti "he finds", with exact cognates in Sanskrit veda and Greek οἴδα, all of which retain their essentially present tense meaning "I know".


The perfective and imperfective aspect classes are together known as eventive, or verbs that depict events, to distinguish them from stative (verbs that depict a state of being). The perfective aspect, also known as perfectus (Latin "finished") or the aorist, was used for completed actions or actions viewed as an entire process. The imperfective aspect was used to describe continuous, durative actions. These eventive aspects were originally not marked for tense; however, the option arose to mark current action with the (later grammaticalized) addition of the hic-et-nunc (Latin "here and now") particle -i to the personal endings of verbs of imperfective aspect. This created a tense contrast among eventive verbs: the unmarked past (durative imperfect tense and non-durative, punctiliar aorist) vs. the present tense marked with terminal affixation of -i in the singular or -s in the plural.

  • Stative class (non-eventive)
    • "Perfect"
  • Perfective class (eventive)
    • "Aorist"
  • Imperfective class (eventive)
    • "Present"
    • "Imperfect"


The moods of PIE included indicative, imperative, optative, and subjunctive.

Indicative Imperative Optative Subjunctive
Function action described as fact commands wishes, hopes action described as completely theoretical
Characteristics default mood personal endings differing from indicative; not conjugated in the first person ablauting -ih1~yeh1- affixed to root; personal endings the same as imperfect/aorist indicative verbs (no -i) thematic (e/o) suffix affixed to root; personal endings the same as present indicative verbs (with suffixed -i)

The place of the injunctive mood, of obscure function, is debated. It takes the form of the bare root in e-grade with the omission of the augment and the hic et nunc particle, which were both tense markers. This causes Fortson (among others) to suggest that the use of the injunctive was for gnomic expressions (as in Homer) or in otherwise timeless statements (as in Vedic).[citation needed]


PIE, like many languages, had a set of conjugational classes for verbs, called "conjugations". In many modern languages, and to a fair extent in Latin, each verb lexeme belongs to a particular conjugation which determines all verb forms. In PIE, however, a verb lexeme would belong to one conjugation for each of the three aspects (imperfective, perfective, stative), with no clear relations among them. This leads to the system of describing a verb by its principal parts, one for each of the conjugational classes that a verb belongs to. (Latin has four principal parts, Ancient Greek six, and Sanskrit at least ten.)

For example, in Sanskrit, there are at least ten present conjugations, seven aorist conjugations, and five perfect conjugations, and in general, knowing the present conjugation of a verb does not help in identifying the aorist or perfect conjugation, and vice versa. Furthermore, especially in Greek and Sanskrit, many verbs are missing some principal parts, and some verbs can be conjugated in some aspects according to multiple conjugations, sometimes with different meanings (see the above example with the Greek verb peithō).

This can also be seen in the third conjugation of Latin, which includes most verbs directly inherited from PIE. In the Latin third conjugation, verbs in the present tense can be either normal or i-stem, while verbs in the perfect can be formed in any of six or so different ways, and there is no general relation between the two.

Primary vs. secondary verbs

A fundamental distinction in PIE was between primary and secondary formations. A primary formation is a word that is formed by adding a suffix directly onto a root (as described above), while a secondary formation is a word formed from an existing word (whether primary or secondary). As an approximate parallel in English, the word contain can be considered a primary formation, created by adding the prefix con- to the root -tain. In turn, the suffix -er can be added onto the word contain to form the secondary formation container. This process can be repeated to form containerize and then containerization. As in the English example, the fundamental difference in PIE between primary and secondary formations is that only the latter are formed from existing words. As in the English root -tain, the PIE roots from which a primary formation is derived are not themselves words, and in fact often exist in multiple variations (cf. -tain vs. -ten-, as in retain vs. retention, or -ceive vs. -cep(t) vs. -cip-, as in receive vs. reception vs. recipient).

Note that this usage of these terms has no relation with the system of primary and secondary endings, and only a partial connection with the distinction between primary and secondary verb categories found in the daughter languages.

Generally, a given suffix can be classified as either primary or secondary, although some suffixes can form both types of words, and in some situations it is not always clear whether a particular word was originally primary or secondary.

In the case of verbs, secondary verbs were formed either from primary verbs (so-called deverbal verbs) or from nouns (denominal verbs or denominative verbs) or adjectives (deadjectival verbs). (In practice, the term denominative verb is often used to incorporate formations based on both nouns and adjectives because PIE nouns and adjectives had the same suffixes and endings, and the same processes were used to form verbs from both nouns and adjectives.) Particular processes of forming secondary verbs had particular meanings such as causative, intensive, and desiderative. The formation of secondary verbs was part of the derivational system rather than the inflectional system, as they existed only for certain verbs and did not necessarily have completely predictable meanings (compare the remnants of causative constructions in English — to fall vs. to fell, to sit vs. to set, to rise vs. to raise and to rear). The above-mentioned verbal nouns and adjectives were likewise part of the derivational system (compare the formation of verbal nouns in English, using -er, -ing, etc.), although in many daughter languages they were incorporated into the inflectional system.

In PIE, secondary verbs existed only in the imperfective system, and had no stative or perfective forms. Even some of the primary verbs were missing stative or perfective forms, or had forms with unpredictable meanings, and many primary verbs had multiple ways of forming some or all of their aspects, sometimes with differences of meaning among the different forms. Furthermore, evidence from the Rig Veda (the earliest attestation of Sanskrit) indicates that secondary verbs in PIE were not conjugated in the subjunctive or optative moods.

Collectively, all of this indicates that in PIE, especially earlier on, all of the aspects and moods were part of the derivational rather than inflectional system. That is, the various "tenses", moods and such were originally independent lexical formations, similar to the way that verbal nouns in English are formed unpredictably from different suffixes, sometimes with two or more formations that may differ in meaning: e.g. reference vs. referral, transference vs. transferral, recitation vs. recital, or delivery vs. deliverance. Furthermore, a basic constraint in the verbal system prohibited applying a derived form to an already-derived form.

Development of the conjugational system

Only later, and gradually, were these various derivational forms combined into a single set of inflectional paradigms. This process proceeded in steps:

  1. Combining different forms with similar meanings into a system of three major aspects. The result of this was the so-called "Cowgill-Rix" system described above, which was completed in late PIE, shortly after Tocharian had split off and well after the Anatolian split. At this stage, formations that originally had various purposes had their semantics largely harmonized into one of the aspect classes, and the system of mood marking was developed. These formations, however, were still separate lexical verbs, still sometimes with idiosyncratic meanings, and for a given aspect class a root could still form multiple or no verbs in that class. This is the stage visible in early Vedic Sanskrit.
  2. Pruning multiple formations, fill in the gaps and combine the formations under a single lexical entry, with a clear distinction between inflectional and derivational forms. At this stage a lexical entry for a single verb was defined by a set of principal parts, each of which (approximately) defined the conjugational class of the given verb in the given tense/aspect. This stage was in process in Vedic Sanskrit and was largely completed in Ancient Greek, although even in this language there are still gaps as well as occasional multiple formations with idiosyncratic meanings. Many remnants of this stage are also found in Old Church Slavonic, which still had distinct stems for the present, aorist and infinitive/participle. Most Slavic languages later lost the aorist, but verbs still have distinct (and unpredictable) present and infinitive stems up to the present day.
  3. Regularizing the formations into "conjugations" that applied across the whole system, so that a verb belonged to a single conjugational class rather than a set of classes. This stage was partly complete in Latin, in particular in regards to the -āre, -ēre, -īre (first, second, fourth) conjugations. The older system, however, is still clearly visible in the -ere class, with each verb in this class, and some in the other classes, needing to be defined by four separate principal parts.
    In Proto-Germanic, this process seemed to have been largely completed, with only a few relic formations such as j-presents and n-infix presents remaining as "irregular" verbs. However, a clear distinction was still maintained between primary and secondary verbs, since the lack of multiple aspect stems in the latter eventually led to the creation of the weak verbs, with most of the original primary verbs becoming strong verbs. A small minority of statives retained their perfect/stative inflection, becoming the preterite-present verbs.
  4. Gradual reduction in the number of conjugational classes, as well as the number of productive classes. This development is very clearly attested in the later Germanic languages. Afrikaans is an extreme example, where almost all verbs follow the same conjugational pattern. English is also a strong example, where all weak verb classes have merged, many older strong verbs have become weak, and all other verbs are considered irregular relic formations. Dutch and German also show this development, but the non-productive strong verb classes have remained more regular. Swedish still retains two weak verb classes, although only one is productive.
    In the Romance languages, these developments have also occurred, but to a lesser degree. The classes are ere êre ire remain productive; the fourth (-īre) though is generally only marginally productive.

The gradual tendency in all of the daughter languages was to proceed through the stages just described, creating a single conjugational system that applied to all tenses and aspects and allowing all verbs, including secondary verbs, to be conjugated in all inflectional categories. Generally, the primary verbs were largely all lumped together into a single conjugation (e.g. the Latin -ere conjugation), while different secondary-verb formations produced all other conjugations; for the most part, only these latter conjugations were productive in the daughter languages. In most languages, the original distinction between primary and secondary verbs was obscured to some extent, with some primary verbs scattered among the nominally secondary/productive conjugations. Germanic is perhaps the family with the clearest primary/secondary distinction: Nearly all "strong verbs" are primary in origin while nearly all "weak verbs" are secondary, with the two classes clearly distinguished in their past-tense and past-participle formations.

Present classes

The most common present stems types according to LIV2.

Primary present-tense verbs

  • Type 1: Simple athematic verbs
    • Type 1a (normal) with alternating normal-grade, root accent and zero-grade, ending accent
    • Type 1b (Narten) with mostly root accent and alternating lengthened/normal grade (according to an alternative view, fixed normal grade throughout)
  • Type 2: Simple thematic verbs
    • Type 2a: Stem-stressed, normal-grade
    • Type 2b: Theme-stressed, zero-grade ("tudati class")
  • Type 3: Reduplicating verbs
    • Type 3a: Athematic, alternating grade and accent as in type 1a
    • Type 3b: Thematic, with fixed zero-grade and theme stress
  • Type 4: Nasal infix/suffix verbs, originally athematic as in type 3a, thematized in many languages according to type 3b. In athematic type, full-grade forms have full grade and accent on the infix/suffix; the root itself is always unstressed, zero-grade.
    • Type 4a: Infix nasal before final consonant of root
    • Type 4b: Same as 4a, but consonant is a laryngeal; evolution in daughter languages divergent from type 4a
    • Type 4c: -nu- suffix formed as if a -w- were added to the root and then a nasal infixed according to type 4a; often forms secondary verbs in the daughter languages.
  • Type 5: Primary -ye- verbs, thematic
    • Type 5a: Full-grade, stem-stressed, mostly transitive
    • Type 5b: Zero-grade, ending-stressed, mostly intransitive and in middle voice
  • Type 9: Primary -sḱe- verbs, thematic
    • Type 9a: Simple -sḱe- verbs
    • Type 9b: Reduplicated -sḱe- verbs
  • Type 11: Primary -se- verbs, thematic

Secondary present-tense verbs

  • Type 6: Factitive/denominative in -ye-, thematic unless otherwise indicated
    • Type 6a: Denominative in -ye- to nouns with ablauting stems; accent on theme.
    • Type 6b: Factitive in -eh₂-(ye)- to adjectives. Originally (in Hittite) athematic without the -ye-, later thematized with -ye- suffix.
    • Type 6c: Denominative in -eh₂-ye- to nouns and adjectives. Apparently began as type-6a denominatives to -eh₂ nouns, but in all daughters reanalyzed as a suffix and formed to multiple types of nouns and adjectives.
    • Type 6d: Factitive in -oye- to adjectives. Possibly nonexistent in PIE.
    • Type 6e: Denominative in -eye- to nouns and adjectives. Apparently began as type-6a denominatives to -os, -om nouns, but in all daughters reanalyzed as a suffix and formed to multiple types of nouns and adjectives. Accented either as -eyé- (early Vedic) or -éye- (later, elsewhere?).
  • Type 7: Causative/iterative in -éye-, with o-grade root.
  • Type 8: Stative in -eh₁-(ye)-. As for -eh₂- factitives, originally (in Hittite) athematic without the -ye-, later thematized with -ye- suffix.
  • Type 9: Inchoative etc. in -sḱe-, thematic
    • Type 9a, 9b: Primary -sḱe- verbs, without/with reduplication (see above)
    • Type 9c: Stative inchoative in -eh₁-sḱe-
    • Type 9d: Other formations in -sḱe-
  • Type 10: Desiderative in -(h₁)se-, mostly thematic; -h₁- usually disappears after stops
    • Type 10a: Simple desiderative in -(h₁)se-
    • Type 10b: Reduplicated desiderative in -(h₁)se-
    • Type 10c: Simple desiderative in -(h₁)s-ye-

Table of outcomes of present classes

NOTE: A blank space means the reflex of the given class in the given language is undetermined. If no reflexes exist, put "no" in the space.

PIE Sanskrit Greek Latin Germ OCS Lith OIr Arm Alb Toch Hitt
1: -
Simple athematic
class II (130) two-syllable -mi verbs (9) 4 or 5 verbs "to be" (*immi), "to do/put" (*dōmi) Class V (4 -mĭ verbs) -mi verbs in OLith. 3 verbs class I common
2: -e-
Simple thematic
2a: class I; 2b: class VI many verbs many -ere verbs most strong verbs class I class B I class II; class III, IV (deponent) no
3a: Ci-CéC-
Reduplicated athematic
class III a few prominent -mi verbs[* 1]
3b: Ci-CC-e-
Reduplicated thematic[* 2]
a few verbs[* 3] a few verbs[* 4] a few verbs[* 5] relics[* 6]
4a: CR̥-néC-
n-infix athematic
class VII CV-n-C-ánō verbs CV-n-Cō verbs relics relics n-infix verbs class B III -an- verbs class VII causative -nin- verbs?
4b: CR̥-néH-
n-infix athematic + laryngeal
class IX -nēmi verbs a few -n verbs 4th weak (fientive) class II (semelfactive -nǫ- verbs) class B IV class VI no?
4c: CR̥-néu-
n-infix athematic + w
class V, VIII -nūmi verbs relics relics class B V causative -nu- verbs
5: primary -ye-
5a: class IV; 5b: passive verbs many *-Cyō verbs 3rd conj. i-stem; part of 4th conj. strong verbs with -j- present a few -ī/ī verbs many verbs? class B II 5b: passive -i- verbs Class iv subjunctive
6a: denom. -Cye- -yáti verbs many *-Cyō verbs (e.g. -ainō, -izdō, -eiō); -iō, -uō class XII from n-nouns
6b/c: factitive/denom. -eh₂-ye-: usually very productive -āyati verbs -aō contract verbs -āre verbs (1st conj.) 2nd weak in -ō- -aj/a- verbs (class III Aa) weak a-verbs (class A I) 6b: athem. factitive
6d: factitive -o-ye-? -oō contract verbs? factitive 3rd weak verbs? "a class of Anatolian denominatives"?[1]
6e: denom. -e-ye-: usually very productive class X; denom. -a-yáti verbs many -eō contract verbs many -īre, a few -ēre verbs denom. 1st weak denom. -ī/ī verbs denom. weak i-verbs (class A II)
7: caus./iter. CoC-é-ye- caus. verbs (very productive) CoC-eō verbs: some iter., a few caus. -ēre caus. verbs caus. 1st weak (common) caus./iter. -ī/ī verbs caus. weak i- verbs (class A II)
8: stative -eh₁-(ye)- -(th)ē- aorist passive most 2nd conj. verbs most 3rd weak verbs -ěj/ě- verbs; impf. -ě- > -a- suffix
9a,b: primary -sḱe- 9a: 13 -cchati verbs 9a: relics; 9b: several verbs 9a: several verbs; 9b: only discō "learn"
9c: -eh₁-sḱe- stative inchoative in -ēscere (productive) a few -oh verbs
9d: other -sḱe- Homeric habitual past -esk- verbs inchoative in -(ī)scere (productive) c`-aorist, -ic`-subjunctive class IX in B; causative in -ṣṣ- (very productive) habitual, durative in -šk- (very productive)
10a,b: desiderative -(h₁)se- esp. 10b: desid. verbs (productive) 10a: future tense relics no? 10b: future tense
10c: desid. -(h₁)sye- future tense no? no? relic: byšęštĭ future tense Gaulish future tense
11: -se- relics relics relics relics relics relics relics relics relics class VIII esp. in A
  1. most prominently, títhēmi "to put" < *dhi-dheh₁-mi, dídōmi "to give" < *di-deh₃-mi, hístēmi "to stand" < *sti-steh₂-mi, híēmi "to send" < *yi-yeh₁-mi.
  2. Many verbs in this class were thematized in individual languages from original athematic verbs, cf. Sanskrit thematic tíṣṭhati "to stand", Latin thematic sistō "to set up" vs. Greek athematic hístēmi "to stand". The cognates of Sanskrit sī́dati "to sit" and píbati "to drink" are thematic in all languages and may be original formations.
  3. e.g. tíṣṭhati "to stand" < *sti-sth₂-eti, sī́dati "to sit" < *si-zd-eti, píbati "to drink" < *pi-bh₃-eti < *pi-ph₃-eti.
  4. e.g. gígnomai "to be born", mímnō "to stay", hízdō "to sit" < *sizd-.
  5. e.g. gignō "to beget", sistō "to set up", sīdō "to sit down" < *sizd-, bibō "to drink" < *bibh₃- < *pibh₃-, serō "to sow" < *sish₁-, reddō "to give back" < *rededō < re- + dedh₃- (Sihler 1995, p. 496).
  6. ibid "to drink" < *pibh₃-.

Aorist classes

  • Type 1: Root aorist
  • Type 2: Sigmatic (-s-) aorist, perhaps with Narten-style lengthened/normal-grade alternation
  • Type 3: Thematic aorist, often with zero-grade root
  • Type 4: Reduplicated aorist, often with a causative meaning

Table of outcomes of aorist classes

NOTE: A blank space means the reflex of the given class in the given language is undetermined. If no reflexes exist, put "no" in the space.

PIE Sanskrit Greek Latin Germ OCS Lith OIr Arm Alb Toch Hitt
1: root class I (predominant in early Vedic; c. 130 attested verbs) root aorist: well-attested no no? < 20 Class I preterite a few presents
2: -s- classes IV, V, VI, VII first aorist s-perfect (to many primary -ere verbs) no sigmatic, productive aorist no s- and t-preterite; in subj., s-subjunctive sigmatic sh-aorist Class III preterite
3: thematic class II (more common in later Vedic) second aorist "aorist-present" verbs (relics) > thematic presents "root aorist" to class I, II highly productive Class VI preterite
4: redup. class III (to causatives) aorist to causatives only dua ‘to love’ class II preterite in Toch. A (usually causative)

Other verbal formations

NOTE: A blank space means the reflex of the given class in the given language is undetermined. If no reflexes exist, put "no" in the space.

PIE Sanskrit Greek Latin Germ OCS Lith OIr Arm Alb Toch Hitt
perfect: Ce-CoC- perfect tense (in Vedic, with present meaning) perfect tense (often with present meaning, esp. in Homer) reduplicated perfect (many verbs); a few perfect-presents preterite tense; preterite-presents (15 verbs) věděti "to know" no? redup. preterite no some Class III preterite; perfect ptc. ḫi-presents
lengthened perfect/aorist in -ē-  ?  ? long-vowel perfect  ?  ?  ?  ?  ?  ? Class II preterite in Toch. B  ?
imperfect imperfect tense (in Vedic, with aorist meaning) imperfect tense no? only dōną "do" no? no? no? aorist, imperfect singular imperfect no? preterite tense?
subjunctive subjunctive (future meaning) subjunctive future of 3rd, 4th conj. no no? a-subj.?; s-subjunctive < aorist subj. no?
optative optative optative im-subj. to athematic verbs subjunctive; also wiljaną "want" imperative imperative ("permissive"?) no optative; plural imperfect optative; imperfect no
imperative yes yes yes yes yes no no yes yes yes yes
-nt- participle: usually active present ptc. yes yes yes yes yes yes only relics no yes meaning like a t-participle
-mh₁n- participle: usually mediopassive present ptc. yes yes only relics no? present passive ptc. in *-mo- yes in OPrus; present passive ptc. in *-mo- only relics present passive ptc. in *-m-?
-wos- participle: usually active past ptc. yes yes -v- perfects[citation needed] no yes yes no yes
-t- past participle (passive for trans. verbs, active for intrans.) to most verbs yes, adjectival force? yes to weak verbs, some adjectives yes yes passive preterite no no
-n- past participle (same meaning as t-participle) to some verbs only relics to strong verbs yes only relics only relics no? no
-l- past participle no no no no active "resultative" no no passive no Toch. A gerundive no
middle voice in -i- in -i- in -r-, passive meaning in -i-, passive meaning no? no? in -r- in -i- in -i- primary endings in -r-, secondary in -i- in -r-
deponent (middle-only) verbs yes yes yes no (*haitaną "to call" in post-Northwest Germanic) yes
dual verbs yes 2nd/3rd person only no 1st/2nd person only yes yes no (nouns only) yes

Proposed endings

At least the following sets of endings existed:

  • Primary athematic
  • Primary thematic
  • Secondary athematic
  • Secondary thematic
  • Perfect
  • Imperative

The primary vs. secondary endings are used in different categories, with primary (or "non-past") endings appearing in the present indicative and throughout the subjunctive, while the secondary (or "past") endings appear in the imperfect indicative, the aorist indicative, and in some or all optative categories. The perfect indicative had its own endings; likewise, the imperative. Note that, from a diachronic standpoint, the secondary endings are actually the more basic ones, while the primary endings were formed from them by adding a suffix, originally -i in the active and -r in the mediopassive (although the more central subfamilies have innovated by extending -i to the mediopassive as well).

The athematic (mi) endings are added directly to the stem, while the thematic (ō) endings use a "thematic vowel" o or e before the endings. Whether thematic or athematic endings are used is a property of a given verb conjugational class. The athematic endings appear to be older, and ablaut within a given paradigm (usually between active singular and all other forms) generally occurs only in athematic classes. The clear tendency in the daughter languages is to extend the thematic endings at the expense of the athematic ones, likely because of the complications resulting from the consonant clusters formed when the mostly consonant-initial endings are added directly onto the mostly consonant-final stems.

Traditional accounts say first-person singular is the only form where the endings differed, except for the presence or absence of the thematic vowel. Newer accounts by Sihler (1995), Fortson (2004) and Ringe (2006) are similar, with the proto-forms modernized using laryngeal notation.Sihler, however, notes that many of the most archaic languages have third-person singular forms missing a t and proposes an alternative t-less thematic ending along with the standard ending. Greek and Balto-Slavic have t-less forms in thematic actives, whereas Vedic and Hittite have t-less athematic middle forms. Beekes (1995), uses the t-less forms as the starting point for a radical rethinking of the thematic endings, based primarily on Greek and Lithuanian. These proposals are still controversial, however.[citation needed]

Primary (non-past) active endings in Proto-Indo-European, according to different authorities
Buck (1933) Sihler (1995) Beekes (1995) Fortson (2004) Ringe (2006)
Athematic Thematic Athematic Thematic Athematic Thematic Athematic Thematic Athematic Thematic
Singular 1st *-mi *-ō *-mi *-oh₂ *-mi *-oH *-mi *-oh₂ *-mi *-oh₂
2nd *-si *-esi *-si *-esi *-si *-eh₁i *-si *-esi *-si *-esi
3rd *-ti *-eti *-ti *-eti/-ei *-ti *-e *-ti *-eti *-ti *-eti
Dual 1st -? -? *-wos *-owos *-ues *-oues *-we- *-owe- *-wos *-owos
2nd -? -? *-th₁es *-eth₁es *-tHes/-tHos *-etHes/-etHos *-to- *-eto- *-tes *-etes
3rd -? -? *-tes *-etes *-tes *-etes *-to- *-eto- *-tes *-etes
Plural 1st *-mos/-mes *-omos/-omes *-mos *-omos *-mes *-omom *-me- *-ome- *-mos *-omos
2nd *-te *-ete *-te *-ete *-th₁e *-eth₁e *-te(-) *-ete(-) *-te *-ete
3rd *-nti *-onti *-nti *-onti *-nti *-o *-nti *-onti *-nti *-onti

A third conjugation has been proposed in Jay Jasanoff's h₂e-conjugation theory.



The following is an example paradigm, based on Ringe (2006), of the verb *leykʷ-, "leave behind" (athematic nasal-infixed present, root aorist, reduplicated perfect). Two sets of endings are provided for the primary medio-passive forms (subjunctive and primary indicative) — the central dialects (Indo-Iranian, Greek, Germanic, Balto-Slavic, Albanian, and Armenian) use forms ending in *y, while the peripheral dialects (Italic, Celtic, Hittite, and Tocharian) use forms ending in *r, which are generally considered the original forms.

Ringe makes certain assumptions about synchronic PIE phonology that are not universally accepted:

  1. Sievers' Law applies in all positions and to all resonants, including *i, *u, *r, *l, *n, *m.
  2. Word-final *t becomes *d when adjacent to a voiced segment (i.e. vowel or voiced consonant).

The effects of the generally-accepted synchronic boukólos rule whereby *kʷ becomes *k next to *u or *w are shown.

Present stem, active
1ary indic. 2ary indic. subjunctive optative imperative
1 sg. *linékʷmi *linékʷm̥ *linékʷoh₂ *linkʷiéh₁m
2 sg. *linékʷsi *linékʷs *linékʷesi *linkʷiéh₁s *linékʷ, *linkʷdʰí
3 sg. *linékʷti *linékʷt *linékʷeti *linkʷiéh₁t *linékʷtu
1 du. *linkuós *linkué *linékʷowos *linkʷih₁wé
2 du. *linkʷtés *linkʷtóm *linékʷetes *linkʷih₁tóm *linkʷtóm
3 du. *linkʷtés *linkʷtā́m *linékʷetes *linkʷih₁tā́m *linkʷtā́m
1 pl. *linkʷm̥ós *linkʷm̥é *linékʷomos *linkʷih₁mé
2 pl. *linkʷté *linkʷté *linékʷete *linkʷih₁té *linkʷté
3 pl. *linkʷénti *linkʷénd *linékʷonti *linkʷih₁énd *linkʷéntu
participle *linkʷónts, *linkʷn̥tés; *linkʷóntih₂, *linkʷn̥tyéh₂s
Present stem, mediopassive
1ary indic. (central) 1ary indic. (peripheral) 2ary indic. subjunctive (central) subjunctive (peripheral) optative imperative
1 sg. *linkʷh₂éy *linkʷh₂ér *linkʷh₂é *linékʷoh₂ey *linékʷoh₂er *linkʷih₁h₂é
2 sg. *linkʷth₂éy *linkʷth₂ér *linkʷth₂é *linékʷeth₂ey *linékʷeth₂er *linkʷih₁th₂é  ?
3 sg. *linkʷtóy *linkʷtór *linkʷtó *linékʷetoy *linékʷetor *linkʷih₁tó  ?
1 du. *linkuósdʰh₂ *linkuósdʰh₂ *linkuédʰh₂ *linékʷowosdʰh₂ *linékʷowosdʰh₂ *linkʷih₁wédʰh₂
2 du.  ?  ?  ?  ?  ?  ?  ?
3 du.  ?  ?  ?  ?  ?  ?  ?
1 pl. *linkʷm̥ósdʰh₂ *linkʷm̥ósdʰh₂ *linkʷm̥édʰh₂ *linékʷomosdʰh₂ *linékʷomosdʰh₂ *linkʷih₁médʰh₂
2 pl. *linkʷdʰh₂ué *linkʷdʰh₂ué *linkʷdʰh₂ué *linékʷedʰh₂ue *linékʷedʰh₂ue *linkʷih₁dʰh₂ué *linkʷdʰh₂ué
3 pl. *linkʷn̥tóy *linkʷn̥tór *linkʷn̥tó *linékʷontoy *linékʷontor *linkʷih₁ró  ?
participle *linkʷm̥h₁nós
Aorist stem, active
2ary indic. subjunctive optative imperative
1 sg. *léykʷm̥ *léykʷoh₂ *likʷyéh₁m
2 sg. *léykʷs *léykʷesi *likʷyéh₁s *léykʷ, *likʷdʰí
3 sg. *léykʷt *léykʷeti *likʷyéh₁t *léykʷtu
1 du. *likwé *léykʷowos *likʷih₁wé
2 du. *likʷtóm *léykʷetes *likʷih₁tóm *likʷtóm
3 du. *likʷtā́m *léykʷetes *likʷih₁tā́m *likʷtā́m
1 pl. *likʷmé *léykʷomos *likʷih₁mé
2 pl. *likʷté *léykʷete *likʷih₁té *likʷté
3 pl. *likʷénd *léykʷonti *likʷih₁énd *likʷéntu
participle *likʷónts, *likʷn̥tés; *likʷóntih₂, *likʷn̥tyéh₂s
Aorist stem, mediopassive
2ary indic. subjunctive (central) subjunctive (peripheral) optative imperative
1 sg. *likʷh₂é *léykʷoh₂ey *léykʷoh₂er *likʷih₁h₂é
2 sg. *likʷth₂é *léykʷeth₂ey *léykʷeth₂er *likʷih₁th₂é  ?
3 sg. *likʷtó *léykʷetoy *léykʷetor *likʷih₁tó  ?
1 du. *likwédʰh₂ *léykʷowosdʰh₂ *léykʷowosdʰh₂ *likʷih₁wédʰh₂
2 du.  ?  ?  ?  ?  ?
3 du.  ?  ?  ?  ?  ?
1 pl. *likʷmédʰh₂ *léykʷomosdʰh₂ *léykʷomosdʰh₂ *likʷih₁médʰh₂
2 pl. *likʷdʰh₂ué *léykʷedʰh₂ue *léykʷedʰh₂ue *likʷih₁dʰh₂ué *likʷdʰh₂ué
3 pl. *likʷn̥tó *léykʷontoy *léykʷontor *likʷih₁ró  ?
participle *likʷm̥h₁nós
Perfect stem, active
indicative subjunctive optative imperative
1 sg. *lelóykʷh₂e *leléykʷoh₂ *lelikʷyéh₁m
2 sg. *lelóykʷth₂e *leléykʷesi *lelikʷyéh₁s  ?, *lelikʷdʰí
3 sg. *lelóykʷe *leléykʷeti *lelikʷyéh₁t  ?
1 du. *lelikwé *leléykʷowos *lelikʷih₁wé
2 du.  ? *leléykʷetes *lelikʷih₁tóm  ?
3 du.  ? *leléykʷetes *lelikʷih₁tā́m  ?
1 pl. *lelikʷmé *leléykʷomos *lelikʷih₁mé
2 pl. *lelikʷé *leléykʷete *lelikʷih₁té  ?
3 pl. *lelikʷḗr *leléykʷonti *lelikʷih₁énd  ?
participle *lelikʷṓs, *lelikusés; *lelikʷósih₂, *lelikusyéh₂s


The following is an example paradigm, based on Ringe (2006), of the verb *bʰer- "carry" in the simple thematic present tense. Two sets of endings are provided for the primary mediopassive forms, as described above.

The above assumptions about PIE phonology apply, in addition to a rule that deletes laryngeals which occur in the sequence -oRHC or -oRH#, where R stands for any resonant, H any laryngeal, C any consonant and # the end of a word. The most important effect of this rule is to delete most occurrences of *h₁ in the thematic optative.

Present stem, active
1ary indic. 2ary indic. subjunctive optative imperative
1 sg. *bʰéroh₂ *bʰérom *bʰérōh₂ *bʰéroyh₁m̥
2 sg. *bʰéresi *bʰéres *bʰérēsi *bʰéroys *bʰére
3 sg. *bʰéreti *bʰéred *bʰérēti *bʰéroyt *bʰéretu
1 du. *bʰérowos *bʰérowe *bʰérōwos *bʰéroywe
2 du. *bʰéretes *bʰéretom *bʰérētes *bʰéroytom *bʰéretom
3 du. *bʰéretes *bʰéretām *bʰérētes *bʰéroytām *bʰéretām
1 pl. *bʰéromos *bʰérome *bʰérōmos *bʰéroyme
2 pl. *bʰérete *bʰérete *bʰérēte *bʰéroyte *bʰérete
3 pl. *bʰéronti *bʰérond *bʰérōnti *bʰéroyh₁end *bʰérontu
participle *bʰéronts, *bʰérontos; *bʰérontih₂, *bʰérontieh₂s
Present stem, mediopassive
1ary indic. (central) 1ary indic. (peripheral) 2ary indic. subjunctive (central) subjunctive (peripheral) optative imperative
1 sg. *bʰéroh₂ey *bʰéroh₂er *bʰéroh₂e *bʰérōh₂ey *bʰérōh₂er *bʰéroyh₂e
2 sg. *bʰéreth₂ey *bʰéreth₂er *bʰéreth₂e *bʰérēth₂ey *bʰérēth₂er *bʰéroyth₂e  ?
3 sg. *bʰéretoy *bʰéretor *bʰéreto *bʰérētoy *bʰérētor *bʰéroyto  ?
1 du. *bʰérowosdʰh₂ *bʰérowosdʰh₂ *bʰérowedʰh₂ *bʰérōwosdʰh₂ *bʰérōwosdʰh₂ *bʰéroywedʰh₂
2 du.  ?  ?  ?  ?  ?  ?  ?
3 du.  ?  ?  ?  ?  ?  ?  ?
1 pl. *bʰéromosdʰh₂ *bʰéromosdʰh₂ *bʰéromedʰh₂ *bʰérōmosdʰh₂ *bʰérōmosdʰh₂ *bʰéroymedʰh₂
2 pl. *bʰéredʰh₂ue *bʰéredʰh₂ue *bʰéredʰh₂ue *bʰérēdʰh₂ue *bʰérēdʰh₂ue *bʰéroydʰh₂ue *bʰéredʰh₂ue
3 pl. *bʰérontoy *bʰérontor *bʰéronto *bʰérōntoy *bʰérōntor *bʰéroyro  ?
participle *bʰéromnos (< *-o-mh₁no-s)

Post-PIE developments

In Greek, the difference between the present, aorist, and perfect, when used outside of the indicative (i.e. in the subjunctive, optative, imperative, infinitive, and participles) is almost entirely one of grammatical aspect, not of tense. That is, the aorist refers to a simple action, the present to an ongoing action, and the perfect to a state resulting from a previous action. An aorist infinitive or imperative, for example, does not refer to a past action, and in fact for many verbs (e.g. "kill") would likely be more common than a present infinitive or imperative. (In some participial constructions, however, an aorist participle can have either a tensal or aspectual meaning.) It is assumed that this distinction of aspect was the original significance of the PIE tenses, rather than any actual tense distinction, and that tense distinctions were originally indicated by means of adverbs, as in Chinese. It appears that by late PIE, the different tenses had already acquired a tensal meaning in particular contexts, as in Greek. In later Indo-European languages, this became dominant.

The meanings of the three tenses in the oldest Vedic Sanskrit differs somewhat from their meanings in Greek, and thus it is not clear whether the PIE meanings corresponded exactly to the Greek meanings. In particular, the Vedic imperfect had a meaning that was close to the Greek aorist, and the Vedic aorist had a meaning that was close to the Greek perfect. Meanwhile, the Vedic perfect was often indistinguishable from a present tense (Whitney 1889). In moods other than the indicative, the present, aorist, and perfect were almost indistinguishable from each other.

The lack of semantic distinction between different grammatical forms in a literary language often indicates that some of these forms no longer existed in the spoken language of the time. In fact, in Classical Sanskrit, the subjunctive dropped out, as did all tenses of the optative and imperative other than the present; meanwhile, in the indicative the imperfect, aorist and perfect became largely interchangeable, and in later Classical Sanskrit, all three could be freely replaced by a participial construction. All of these developments appear to reflect changes in spoken Middle Indo-Aryan; among the past tenses, for example, only the aorist survived into early Middle Indo-Aryan, which was later displaced by a participial past tense.

See also


  1. Ringe, From Proto-Indo-European to Proto-Germanic, p. 180


  • Beekes, Robert S. P. (1995), Comparative Indo-European Linguistics, Amsterdam: John Benjamins, ISBN 90-272-2150-2<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  • Buck, Carl Darling (1933), Comparative Grammar of Greek and Latin, University of Chicago Press, ISBN 0-226-07931-7<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  • Fortson, Benjamin W., IV (2004), Indo-European Language and Culture, Blackwell Publishing, ISBN 1-4051-0316-7<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  • Jasanoff, Jay H. (2003), Hittite and the Indo-European Verb, Oxford University Press, ISBN 0-19-924905-9<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  • Ringe, Don (2006), From Proto-Indo-European to Proto-Germanic, Oxford University Press, ISBN 978-0-19-955229-0<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  • Sihler, Andrew L. (1995), New Comparative Grammar of Greek and Latin, Oxford University Press, ISBN 0-19-508345-8<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  • Watkins, Calvert (1969), Indo-European Origins of the Celtic Verb, Dublin Institute for Advanced Studies, ISBN 0-901282-24-3<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  • Whitney, William Dwight (1889), Sanskrit Grammar, Harvard University Press, ISBN 0-486-43136-3<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>