The infinitive is the base form of a French verb, equivalent to the English “to ” form (e.g., “to eat,” “to go”). It ends in -er, -ir, or -re* and cannot stand alone as a finite verb.
- The infinitive is never conjugated; it appears in dictionary form.
- It can function as a noun, e.g., Le plus dur est de partir (“The hardest part is leaving”).
- It is used after certain verbs, prepositions, and expressions.
- French has two infinitives: the present infinitive and rare past infinitive.
Uses of the Infinitive
The infinitive appears in various grammatical contexts without being tied to a specific subject.
- After conjugated verbs, to express purpose, intention, or as a complement.
- After prepositions like à, de, pour, avant de.
- As the subject or object of a sentence.
- In impersonal expressions and instructions.
- In compound tenses, with avoir or être, to indicate completed action relative to the main verb.
Structure of the Present Infinitive
French infinitives are formed by adding endings to the verb root:
| Group | Ending | Examples |
|---|---|---|
| st group | -er | parler, aimer, chanter |
| nd group | -ir | finir, choisir, grandir |
| rd group | -re | vendre, attendre, répondre |
- The root is found by removing the ending.
- Most verbs belong to the -er group.
- Stem changes (e.g., envoyer) appear only in finite forms, not in the infinitive.
Conjugations in Compound Infinitives
When forming a past infinitive, use avoir or être in the infinitive, plus the past participle:
| Infinitive | Example | English |
|---|---|---|
| avoir + past participle | avoir mangé | to have eaten |
| être + past participle | être parti | to have left |
- Use être for reflexive verbs and certain movement verbs (e.g., aller, venir).
- The past participle agrees in gender and number if the infinitive precedes a noun or pronoun.
Verbs Followed by the Infinitive
Many verbs require an infinitive as their complement without a preposition; others need à or de.
| Followed Directly by Infinitive | Followed by à + Infinitive | Followed by de + Infinitive |
|---|---|---|
| vouloir (to want) | commencer à (to begin) | arrêter de (to stop) |
| pouvoir (can) | apprendre à (to learn) | décider de (to decide) |
| devoir (must) | aider à (to help) | éviter de (to avoid) |
| espérer (to hope) | réussir à (to succeed) | finir de (to finish) |
- Memorize common patterns to avoid errors.
- Some verbs change meaning depending on the preposition used.
Infinitive Phrases and Prepositions
Infinitive phrases often include prepositions that clarify meaning.
- avant de + infinitive: before doing something
- après + avoir/être + past participle: after having done something
- pour + infinitive: in order to
- sans + infinitive: without doing something
Examples:
- Avant de partir, fais tes devoirs.
- Après avoir mangé, il s’est couché.
- Je téléphone pour réserver une table.
- Il est parti sans dire au revoir.
Infinitive vs. Subjunctive
After que (that), use the subjunctive with different subjects; if the subject is the same, use de + infinitive.
- Il faut que tu viennes. (subjunctive)
- Il faut venir tôt. (infinitive, impersonal)
- Je veux que tu partes. (subjunctive)
- Je veux partir maintenant. (infinitive)
Rules:
- Use subjunctive in dependent clauses with que and different subjects.
- Use infinitive after conjugated verbs when the subject does not change.
- Use de + infinitive after some impersonal expressions.
When do you use the subjunctive after que instead of the infinitive in French?
- Use the subjunctive when there are two different subjects joined by que; use the infinitive if the subject is the same.
- Subjunctive appears after que with different subjects; infinitive is used when the subject of both verbs is identical.
French uses the subjunctive after que when two different subjects are involved. If the subject remains the same, the infinitive is used instead.
Other Metas
- Some reflexive verbs appear as se + infinitive (e.g., se laver).
- Modern grammar sometimes describes infinitive uses as “subjunctive without que,” but traditional rules still apply.
- Idioms and literary styles may use the infinitive in unusual ways (e.g., à vous de jouer!).
Summary
The infinitive is the non-conjugated base form of French verbs, used widely across grammar.
- It appears after certain verbs and prepositions, as a noun, and in compound forms.
- Pay attention to verbs that require à or de before the infinitive.
- The past infinitive expresses an action completed before the main verb.
- Use subjunctive after que with different subjects; otherwise, infinitive often applies.
- Practice with examples to internalize patterns.
Flashcards (1 of 2)
- Infinitive: avoir + past participle
- Example: avoir mangé
- English: to have eaten
Last updated: Wed Jun 18, 2025
