Romance verbs are the most inflected part of speech in the language family. In the transition from Latin to the Romance languages, verbs went through many phonological, syntactic, and semantic changes. Most of the distinctions present in classical Latin continued to be made, but synthetic forms were often replaced with more analytic ones. Other verb forms changed meaning, and new forms also appeared.

Overview

The following table presents a comparison of the conjugation of the regular verb cantare "to sing" in Classical Latin, and Vulgar Latin (reconstructed as Proto-Italo-Western Romance, with stress marked), and nine modern Romance languages. The conjugations below were given from their respective Wiktionary pages. Note that the Vulgar Latin reconstructions are believed to have regularized word stress within each tense (except the present and imperative). Word-final ⟨e⟩ probably converged on. Many verb forms have undergone elisions, like the indicative pluperfect cantāveram > *cantára and the subjunctive imperfect cantāvissem > *cantásse.

Vulgar Latin

In this section, "Vulgar Latin" is actually reconstructed as reconstructed Proto-Italo-Western Romance, most notably the shift from Classical Latin -i- and -u- to -e- /e/ and -o- /o/, as opposed to inherited /ɛ/ and /ɔ/ respectively. The developments include: In the Proto-Romance grammatical tradition, the second and third conjugation are known as third conjugation, similarly to French.

First conjugation

Verbs in the first conjugation are in -āre (*-áre), later evolved to -are in Italian, -ar in most Romance languages and -er in French.

Second conjugation

Verbs in the second conjugation are in -ēre (*-ére), later evolved to -ere in Italian, -er in most Romance languages and -oir in French (no "regular" -oir verbs). Another infinitive -ere has merged into this paradigm.

Third conjugation

Verbs in the third conjugation are in -ere (-ere, caused stress in previous syllable), later merged with -ere (-ere, causes stress in antepenultimate syllable), but -re in French and Catalan. The suffix -re in French are in the third group, also known as irregular verbs. The -iō variant (*-io in Vulgar Latin) now defunct, later merged with the second conjugation; the paradigm now only exists in some descendants of the verb faciō.

Fourth conjugation

Verbs in the fourth conjugation are in -īre (*-íre), later evolved to -ire in Italian, and -ir in most Romance languages. This conjugation type are infixed with once-inchoative -īsc- → *-ísc- in some languages, but its placement varies. In Italian, Catalan, and Romanian, the infix -isc-; -esc-, -eix- (Catalan), and -ăsc- (Romanian) is placed on once-stressed indicative and subjunctive present forms (the first-, second-, third-singular and third plural present tenses), and stressed imperatives. In French, the infix -iss- is placed on all indicative present forms, the indicative imperfect, the subjunctive present, and plural imperatives. While there are few non-infixed -īre verbs (also known are pure -īre verbs), in French the infixed verbs are the only regular verbs, otherwise irregular.

Modern languages

While the nominal morphology in Romance languages is primarily agglutinative, the verbal morphology is fusional. The verbs are highly inflected for numbers (singular and plural), persons (first-, second-, and third-person), moods (indicative, conditional, subjunctive, and imperative), tenses (present, past, future), and aspects (imperfective and perfective). Because of the complexities in Romance conjugation, certain languages have a separate article regarding these conjugations: While there are 4 regular infinitives in Classical Latin, namely -āre, -ēre, -ere, and -īre, some of these infinitive were merged. In many Romance languages including Spanish and Portuguese, the main infinitives are -ar, -er, and -ir, with addition of -ôr (Portuguese only) which only exists in the verb, traditionally considered as -er verbs. While in Italian, the infinitives are -are, -ere, -ire. The infinitives -er and -ere (Italian) resulted from the merge of Latin infinitives -ēre and -ere. In French, the infinitives are -er, -oir, -re, -ir, but verbs with -oir and -re are in the third group, also known as irregular verbs. Latin deponent verbs like and (infinitive sequī, nascī) changed to active counterparts *séquo and *násco (infinitive *séquere, *nascere), as in Portuguese, Spanish , and Italian ; and Portuguese , Spanish , and French.

Irregularities

In many Romance languages, verb stems ending in -c, -z shown above were regularly altered to preserve its pronunciation. However, it is not considered irregular.

True irregular verbs

Copula

While the passive voice became completely periphrastic in Romance, the active voice has been morphologically preserved to a greater or lesser extent. The tables below compare the conjugation of the Latin verbs and in the active voice with that of the Romance copulae, their descendants. For simplicity, only the first person singular is listed for finite forms. Note that certain forms in Romance languages come from the suppletive sources sedeo (to be seated) instead of sum, e.g. subjunctive present: sedea > sia, sea, seja... (medieval Galician-Portuguese, for instance, had double forms in the whole conjugation: sou/sejo, era/sia, fui/sevi, fora/severa, fosse/sevesse...)

Other irregular verbs

This is the Vulgar Latin conjugation of the verb *avére: Notice that these forms sometimes also have an inconsistent form, as the table above more resembling with that of French.

Semantic changes

In spite of the remarkable continuity of form, several Latin tenses have changed meaning, especially subjunctives. The Latin imperfect subjunctive underwent a change in syntactic status, becoming a personal infinitive in Portuguese and Galician. An alternative hypothesis traces the personal infinitive back to the Latin infinitive, not to a conjugated verb form.

Periphrases

In many cases, the empty cells in the tables above exist as distinct compound verbs in the modern languages. Thus, the main tense and mood distinctions in classical Latin are still made in most modern Romance languages, though some are now expressed through compound rather than simple verbs. Some examples, from Romanian: New forms also developed, such as the conditional, which in most Romance languages started out as a periphrasis, but later became a simple tense. In Romanian, the conditional is still periphrastic: aș fi, ai fi, ar fi, am fi, ați fi, ar fi.