The verb expresses an action, a state, an occurrence or a change. In Marie court, court tells what Marie does. In Paul est fatigué, est describes a state. In Il arrive demain, arrive marks an event. In La température baisse, baisse indicates a change. The verb also carries conjugation, so it varies according to person, tense, and mood. Without a conjugated verb, the sentence is not anchored in time. The verb is the core of the sentence around which the subject, the complements and the other elements are organized.

The infinitive is the base form of the verb, the one you find in the dictionary. It does not change according to the subject. It is often recognizable by -er, -ir, -re or -oir. Manger, finir, vendre and pouvoir are infinitives. To classify a verb, you always start from this form before conjugating it. The infinitive also serves after another verb in a verbal construction, as in je veux partir or nous pouvons venir. It also appears after a preposition in uses like avant de dormir.

Identification of the base form

Idea
The infinitive is the base form of the verb before conjugation.
The infinitive does not change according to the subject in the sentence.
The infinitive allows classifying the verb before conjugating.

First-group verbs end in -er, except aller. It is the most productive regular model of French. Their stem generally remains stable, then the conjugation endings are added. In the present, we have je parle, tu parles, il parle, nous parlons, vous parlez, ils parlent. The endings are -e, -es, -e, -ons, -ez, -ent. The same pattern is found in aimer, chanter, travailler or habiter. This group serves as the basis for understanding regular conjugation, as in Regular verbs.

Subject	Infinitive	Conjugation
je	danser
nous	danser
il	danser
ils	danser
tu	danser
vous	danser

Present tense conjugation of the first group

Subject	Infinitive	Conjugation
je	danser	danse
tu	danser	danses
il	danser	danse
nous	danser	dansons
vous	danser	dansez
ils	danser	dansent

Scramble

Second-group verbs end in -ir and follow the model of finir. Their present participle ends in -issant. You see it in finissant, choisissant, grandissant. In the present, the endings are -is, -is, -it, -issons, -issez, -issent. We say je finis, tu finis, il finit, nous finissons, vous finissez, ils finissent. Verbs like choisir, réussir, grandir and bâtir follow this pattern. Their stem may appear in a slightly different form before -issons, but the structure remains regular. To review the basic mechanisms, you can also compare with Regular verbs.

Subject	Infinitive	Conjugation
il	grandir
je	grandir
vous	grandir
ils	grandir
tu	grandir
nous	grandir

Present tense conjugation of the second group

Subject	Infinitive	Conjugation
je	grandir	grandis
tu	grandir	grandis
il	grandir	grandit
nous	grandir	grandissons
vous	grandir	grandissez
ils	grandir	grandissent

Scramble

The 3rd group gathers all verbs that do not fit into the first two groups. There we find verbs in -re, like vendre, attendre and prendre, but also verbs in -ir that do not follow the finir model, such as venir and ouvrir. Verbs in -oir also belong to this group, like pouvoir, vouloir and voir. This group is heterogeneous, because its verbs do not have a single conjugation model. Radical changes, irregular endings and particular forms are frequent here. The most common French verbs often belong to this group, which makes it central for Irregular verbs.

Classification of third-group verbs

Idea
Verbs ending in -re often belong to the third group.
Verbs that do not follow the first two groups also go into the third group.
The third group contains very varied and often capricious verbs.

A regular verb follows a predictable pattern: the stem remains stable and the endings repeat. This is the case for most 1st-group verbs and many 2nd-group verbs. An irregular verb modifies its stem, its endings or both. In very common verbs, these irregularities often appear. Être, avoir, aller, faire, venir, pouvoir, vouloir and prendre are verbs essential to recognize early. They are used everywhere in daily language and in constructions such as Verbal constructions, Past participle, Gerund and Pronominal verbs.

Differences between regular and erratic forms

Usage	Explanation
Regular verb	It is used when the conjugation follows a stable and predictable pattern.
Irregular verb	It is used when the form changes more and does not follow the expected pattern.
Common third-group verb	It is used to remind that very common verbs can still belong to the third group.