Proto-Indo-European verbs

Athematic and thematic verbs

Verbs, like nominals, made a basic distinction between thematic and athematic conjugations.

• Thematic verbs were characterised by a vowel (the "thematic vowel") appearing at the end of the stem, before the ending. Some of the endings differed depending on whether this vowel was present or absent, but by and large the endings were the same for both types. The thematic vowel was either e or o, according to a predictable distribution: e appeared before coronal consonants and word-finally (in the second-person singular imperative, which had no ending), and o elsewhere.

• Athematic verbs appear to be older, and show ablaut within the paradigm. In the descendant languages, athematic verbs were often extended with a thematic vowel, likely because of the complications resulting from the consonant clusters formed when the mostly consonant-initial endings were added directly onto the mostly consonant-final stems.

Consequently, the athematic verbs became a non-productive relic class in the later Indo-European languages. In groups such as Germanic and Italic, the athematic verbs had almost gone entirely extinct by the time of written records, while Sanskrit and Ancient Greek preserve them more clearly.

Active eventive endings

Middle eventive endings

Stative endings

A second conjugation has been proposed in Jay Jasanoff's h₂e-conjugation theory. Svensson (2001) suggests *-h₂éy for the second and third dual stative endings, on the basis of evidence from Indo-Iranian, Tocharian, and Gaulish.^[1]

Eventive verbs

The perfective ("aorist") and imperfective ("present") aspect classes are together known as eventive, or verbs that depict events, to distinguish them from stative (verbs that depict a state of being). Both shared the same conjugation, with some small differences. The main difference was that imperfective verbs allowed the use of special present-tense (primary) endings, while perfective verbs only allowed the default tenseless (secondary) endings.

The present tense used the primary eventive endings, and was used specifically to refer to present events, although it could also refer to future events.

The past tense referred to past events, and used the secondary eventive endings. Perfective verbs always used the secondary endings, but did not necessarily have a past-tense meaning. The secondary endings were, strictly speaking, tenseless, even in imperfective verbs.

This meant that past endings could also be used with a present meaning, if it was obvious from context in some way. This use still occurred in Vedic Sanskrit, where in a sequence of verbs only the first might be marked for present tense (with primary endings), while the remainder was unmarked (secondary endings). If the verbs were subjunctive or optative, the mood markings might likewise be only present on the first verb, with the others not marked for mood (i.e. indicative).

In Ancient Greek, Armenian and Indo-Iranian, the secondary endings came to be accompanied by a prefixing particle known as the augment, reconstructed as *e- or *h₁e-. The function of the augment is unclear, but it was not a fixed part of the inflection as it was in the later languages. In Homeric Greek and Vedic Sanskrit, many imperfect (past imperfective) and aorist verbs are still found lacking the augment; its use became mandatory only in later Greek and Sanskrit.

Morphologically, the indicative of perfective verbs was indistinguishable from the past indicative of imperfective verbs, and it is likely that in early stages of PIE, these were the same verb formation. At some point in the history of PIE, the present tense was created by developing the primary endings out of the secondary endings. Not all verbs came to be embellished with these new endings; for semantic reasons, some verbs never had a present tense. These verbs were the perfective verbs, while the ones that did receive a present tense were imperfective.

Stative verbs

Stative verbs signified a current state of being rather than events. 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 static aspect 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.

Like the perfective verbs, stative verbs were tenseless, and described a state without reference to time. This did not mean that stative verbs referred to permanent states (as in Spanish ser versus temporary estar), but rather that there was no way to express, within the verbal morphology, whether the state was applicable in the present moment, in the past, or in the future. These nuances were, presumably, expressed using adverbs.

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, Ancient Greek oída, and Old Church Slavonic ведѣ, all of which retain their essentially present tense meaning "I know".

Voice

Verbs originally had two voices: active and mediopassive. In some daughter languages (e.g., Sanskrit) this was supplemented with a passive voice; in others (e.g., Latin) the mediopassive evolved to have a passive meaning for roots that were also used in the active voice, but retained its mediopassive character for so-called deponent roots.

Mood

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

Root verbs

The most basic verb formation was derived directly from the root, with no suffix, and expressed the meaning of the root itself.

Such "root verbs" could be either athematic or thematic; it was not predictable which type was used. The aspect of a root verb was determined by the root itself, which had its own "root aspect" inherent in the basic meaning of the root.

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.

Stative roots were rare; perhaps the only reconstructible stative root verb was *wóyd- "know".

There are numerous unexplained surprises in this system, however. The common root *h₁es- meant "to be", which is an archetypically stative notion. Yet, aspect-wise, it was an imperfective root, and thus formed an imperfective root verb *h₁és-ti, rather than a stative verb.

Primary derivations

In early PIE, the aspect system was less well-developed, and root verbs were simply used in their root aspects, with various derivational formations available for expressing more specific nuances.

By late PIE, however, as the aspect system evolved, the need had arisen for verbs of a different aspect than that of the root. Several of the formations, which originally formed distinct verbs, gradually came to be used as "aspect switching" derivations, whose primary purpose was to create a verb of one aspect from a root of another aspect.

This led to a fundamental distinction in PIE verb formations, between primary and secondary formations. Primary formations included the root verbs and the derivational formations that came to be used as aspect switching devices, while secondary formations remained strictly derivational and retained significant semantic value.

For example, the secondary suffix *-éye- derived causative verbs, and retained this purpose and meaning throughout the descendants of PIE. The common primary suffix *-ye-, however, came to be used for the majority of verb formations in Latin, without any discernible meaning being conveyed by the suffix; its function had become purely morphological.

A verb needed no derivational or aspect-switching markers for its own root aspect. Affixes of various types were used to switch the inherent aspect to a different type. Such affixes created "characterised" verb formations, contrasting with the basic "root" or "uncharacterised" formation.

Examples of aspect switching affixes include -yé-, -sḱé-, 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 the aspect. For example, the s-aorist also seemed to have been used when the verb root was inherently perfective already.

A root did not necessarily have verbs to express all three aspects. There were many roots that seem to have had verbs for only for one or two aspects in PIE. For example, the root *h₁es- "to be" seems to have formed only an imperfective verb, no perfective or stative verbs derived from this root 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" to fill in as the perfective aspect of *h₁es-, while the Germanic languages used the root *h₂wes- "to live, to reside" in that role.

While 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 root verb 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 verb required a derivational marker to put it into the imperfective aspect. For this root, the imperfective aspect switcher was often reduplication (Ancient Greek hístēmi, 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. Such discrepancies suggest that in PIE proper, this root had no imperfective verb at all, and the aspect-switched verbs we see in the later descendants were formed independently of each other.

Many primary formations retained some "residue" of their original derivational function and meaning, and significant relics of this earlier derivational system can be reconstructed for PIE. The perfective root *gʷem- "to step" is reconstructible with two different imperfective derivations: *gʷm̥-sḱé- (Ancient Greek báskō, Sanskrit gácchati) and *gʷm̥-yé- (Ancient Greek baínō, Latin veniō). Both formations survived side-by-side in Greek, suggesting that they did not overlap significantly enough in meaning throughout their history for one or the other to fall out of use.

Secondary derivations

Secondary verbs were formed either from primary verb roots (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.) Deverbal formations included causative ("I had someone do something"), iterative/inceptive ("I did something repeatedly"/"I began to do something"), desiderative ("I want to do something").

The formation of secondary verbs remained part of the derivational system 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).

They 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. However, as mentioned above, this distinction was only beginning to develop 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.

Secondary verbs were always imperfective, and had no corresponding perfective or stative verbs, nor was it possible (at least within PIE) to derive such verbs from them. This was a basic constraint in the verbal system that prohibited applying a derived form to an already-derived form. 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. This suggests that these moods follow the same constraint, and are derivational in origin. The later Indo-European languages worked around these limitations, but each in their own way.

Primary imperfective

The most common present stems types according to LIV².

Secondary imperfective

Perfective

Stative

*leykʷ-

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.

*bʰer-

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 middle 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.

Developments of the various verb 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.

Germanic

In Germanic, all eventive verbs acquired primary indicative endings, regardless of the original aspectual distinction. These became the "present tense" of Germanic. Almost all presents were converted to the thematic inflection, using the singular (e-grade) stem as the basis. A few "tudati"-type thematic verbs survived (*wiganą "to battle", *knudaną "to knead"), but these were usually regularised by the daughter languages. Of the athematic verbs, only three verbs are reconstructable:

• *wesaną "to be" (present *immi, *isti, from imperfective *h₁ésmi, *h₁ésti),
• *beuną "to be, to become" (present *biumi, *biuþi, from perfective **bʰewHm, **bʰewHt)
• *dōną "to do, to put" (present *dōmi, *dōþi, from perfective *dʰéh₁m̥, *dʰéh₁t).

The merger of perfective and imperfective verbs brought root verbs in competition with characterised verbs, and the latter were generally lost. Consequently, Germanic has no trace of the s-suffix perfectives, and very few characterised primary imperfectives; by far the most primary verbs were simple root verbs. Some imperfectives with the ye-suffix survived into Proto-Germanic, as did one nasal-infix verb (*standaną "to stand" ~ *stōþ), but these were irregular relics. Other characterised presents were preserved only as relic formations and generally got converted to other verbal formations. For example, the present *pr̥skéti "to ask, to question" was preserved as Germanic *furskōną, which was no longer a simple thematic verb, but had been extended with the class 2 weak suffix -ō-.

Stative verbs became the "past tense" or "preterite tense" in Germanic, and new statives were generally formed to accompany the primary eventives, forming a single paradigm. A dozen or so primary statives survived, in the form of the "preterite-present verbs". These retained their stative (in Germanic, past or preterite) inflection, but did not have a past-tense meaning. The past tense ("imperfect") of the eventive verbs was entirely lost, having become redundant in function to the old statives. Only one single eventive past survives, namely of *dōną: *dedǭ, *dedē, from the past reduplicated imperfective *dʰédʰeh₁m̥, *dʰédʰeh₁t.

Secondary eventives (causatives, denominatives etc.) did not have any corresponding stative in PIE and did not acquire one in Germanic. Instead, an entirely novel formation, the so-called "dental past", was formed to them (e.g. *satjaną "to set" ~ *satidē). Thus, a clear distinction arose between "strong verbs" or primary verbs, which had a past tense originating from the statives, and "weak verbs" or secondary verbs, whose past tense used the new dental suffix. The original primary statives (preterite-presents) also used the dental suffix, and a few primary ye-suffix presents also came to use the weak past rather than the strong past, such as *wurkijaną "to work" ~ *wurhtē and *þunkijaną "to think, to consider" ~ *þunhtē. However, these verbs, having no secondary derivational suffix, attached the dental suffix directly to the root with no intervening vowel, causing irregular changes through the Germanic spirant law. Ending-wise, the strong and weak pasts converged on each other; the weak past used descendants of the secondary eventive endings, while the strong past preserved the stative endings only in the singular, and used secondary eventive endings in the dual and plural.