What is an infinitive in French?

The unconjugated form of the verb, ending in -er, -ir, -re, or -oir: parler, finir, vendre, voir. It carries no person and no tense, and it is the form you look up in a dictionary and the form the future and conditional are built from.

When do you use à or de before an infinitive?

It depends on the verb in front, not on the infinitive. Commencer, réussir, and apprendre take à: j'ai réussi à finir. Oublier, décider, and refuser take de: elle a décidé de partir. Vouloir, pouvoir, devoir, and aller take nothing at all.

Why does French use the infinitive where English uses -ing?

Because French keeps its -ant form for a narrower job. After a preposition, as a subject, or as the object of another verb, the slot belongs to the infinitive: sans parler, voyager coûte cher, j'aime lire. Only en takes the participle, as in en parlant.

How do you make an infinitive negative in French?

Put ne pas in front of it as a single block: ne pas fumer, il préfère ne pas répondre. The two words stay together, unlike with a conjugated verb where they wrap around it.

Where do object pronouns go with an infinitive?

Immediately before the infinitive, because that is the verb they belong to: je vais te le dire, il faut les acheter. Putting them in front of the conjugated verb, as in je te vais dire, is one of the clearest signs of a learner sentence.

French grammar · Beginner

The French Infinitive: Forms, Uses, and What Comes Before It

Written by Camille Laurent, Lead French Curriculum Editor · Reviewed May 2026

The infinitive is the verb before anything has been done to it: no person, no tense, no mood. French infinitives end in -er, -ir, -re, or -oir, and in a sentence the infinitive is almost always the second verb, the one depending on a conjugated verb or on a preposition.

J'aimerais apprendre à jouer du piano.

I'd like to learn to play the piano.

What it is

An infinitive names the action and nothing else. It is the form dictionaries list, and it is also the raw material for other forms — the future and the conditional are the infinitive with endings bolted on. Inside a sentence its job is to be the dependent verb: something else is conjugated, and the infinitive follows it.

Je dois partir avant de manger. — I have to leave before eating.

How to spot it

Look for -er, -ir, -re, or -oir on a verb that is not carrying a person. It will be sitting after a conjugated verb, after a preposition, or standing alone as an instruction.

Il faut travailler. — You have to work.
Elle a décidé de rester. — She decided to stay.
Sans réfléchir, il a dit oui. — Without thinking, he said yes.
Fumer est interdit ici. — Smoking is prohibited here.

In the last example the infinitive is the subject of the sentence. English needs -ing to do that; French uses the plain infinitive.

Infinitive Quick Reference

Infinitive endings, and the forms the infinitive itself has

Family or form	Example	English
-er infinitives (about nine in ten)	parler	to speak
-ir infinitives	finir, dormir	to finish, to sleep
-re infinitives	vendre, prendre	to sell, to take
-oir infinitives	voir, devoir	to see, to have to
Present infinitive	faire	to do
Past infinitive	avoir fait	to have done
Passive infinitive	être fait	to be done
Negative infinitive	ne pas faire	not to do

Common Infinitive Examples in French

The four positions an infinitive turns up in:

After a Conjugated Verb

Je veux rentrer.: I want to go home.
Nous espérons vous revoir.: We hope to see you again.
Il sait nager.: He can swim.
Tu dois te reposer.: You need to rest.

Vouloir, pouvoir, devoir, savoir, espérer, and aller take a bare infinitive with nothing in between. English always has a to there, which is what makes this pattern feel unfinished at first.

After a Preposition

Il est parti sans dire au revoir.: He left without saying goodbye.
Je t'appelle avant de partir.: I'll call you before leaving.
Elle travaille pour payer ses études.: She works to pay for her studies.
Au lieu de te plaindre, agis.: Instead of complaining, do something.

Every French preposition except en is followed by an infinitive. En is the lone exception and takes a present participle: en partant.

After À and De with Particular Verbs

J'ai commencé à comprendre.: I've started to understand.
Elle a oublié de fermer la porte.: She forgot to close the door.
On m'a demandé d'attendre.: I was asked to wait.
Ils ont réussi à convaincre le jury.: They managed to convince the panel.

Which preposition a verb takes has to be learned alongside the verb. Commencer à and finir de cannot be worked out from their meanings.

Standing on Its Own

Ne pas déranger.: Do not disturb.
Voir page douze.: See page twelve.
Partir maintenant serait une erreur.: Leaving now would be a mistake.
Que faire ?: What is to be done?

As a subject, an instruction, or a question with no subject, the infinitive behaves like a noun.

How Infinitives Work in a Sentence

The infinitive itself never changes, so everything interesting happens to the words around it.

It Carries No Person and No Tense

Only the first verb in the chain conjugates. Change the subject and the infinitive stays exactly as it was, which is why long French sentences can string several infinitives together without any further agreement.

Il veut partir ; elles veulent partir.

He wants to leave; they want to leave.

One conjugated verb, then infinitives.

Object Pronouns Go in Front of It

The pronoun belongs to the verb it is the object of, so it attaches to the infinitive rather than to the conjugated verb. Je vais le donner, not je le vais donner.

Je vais le lui donner.

I'm going to give it to him.

Pronouns cling to the infinitive.

Ne Pas Stays Together in Front

A negated infinitive keeps both negative words ahead of it as a block. They only separate around a conjugated verb, and an infinitive is not one.

Il m'a dit de ne pas venir.

He told me not to come.

ne pas + infinitive, both leading.

The Preposition Belongs to the First Verb

Whether you need à, de, or nothing is a property of the governing verb, not of the infinitive. Two verbs with almost the same meaning can demand different prepositions, so the answer is always found by looking at the first one.

Je refuse de signer, mais j'accepte d'attendre.

I refuse to sign, but I agree to wait.

Look up the first verb, not the second.

The Infinitive Has a Past Form

Avoir or être plus a past participle gives a past infinitive, used when the action is already over: après avoir mangé, merci d'être venu. It is what French uses instead of an English perfect gerund.

Merci d'être venu si vite.

Thank you for coming so quickly.

avoir / être + participle = past infinitive.

Common Mistakes with Infinitive

Incorrect: Avant partir, j'ai fermé la porte. — Before leaving, I closed the door.

Correct: Avant de partir, j'ai fermé la porte. — Before leaving, I closed the door.

Avant needs de in front of an infinitive, and so do au lieu de, afin de, and près de. Sans, pour, and par take the infinitive directly, which is what makes the pattern look inconsistent.

Incorrect: Je veux de partir. — I want to leave.

Correct: Je veux partir. — I want to leave.

Vouloir governs a bare infinitive. The to in English to leave invites a translation as de or à, but whether anything is needed depends entirely on the first verb, and vouloir needs nothing.

Incorrect: Nageant est bon pour la santé. — Swimming is good for your health.

Correct: Nager est bon pour la santé. — Swimming is good for your health.

A French subject cannot be a present participle. Where English uses -ing as a noun, French uses the infinitive, which is also why fumer est interdit and not fumant est interdit.

Incorrect: Il m'a dit de venir pas. — He told me not to come.

Correct: Il m'a dit de ne pas venir. — He told me not to come.

A negated infinitive keeps ne and pas together in front of it. They split apart only around a conjugated verb, as in il ne vient pas.

The Infinitive as a Noun, an Order, and a Question

Outside the second-verb slot, the infinitive takes on three jobs English handles with other machinery.

As a noun or a subject

Where English turns a verb into a noun with -ing, French uses the infinitive. It can be the subject of the sentence, the object of another verb, or half of a comparison.

Voyager coûte cher.: Travelling is expensive.
Mentir ne sert à rien.: Lying is pointless.
J'aime lire le soir.: I like reading in the evening.
Vouloir, c'est pouvoir.: Where there's a will, there's a way.

A handful of infinitives have hardened into full nouns and take articles: le devoir, le pouvoir, le savoir, le déjeuner, le souvenir.

As a printed instruction

Recipes, labels, and public notices use the infinitive because it has no addressee, and therefore no choice to make between tu and vous.

Battre les œufs en neige.: Whisk the egg whites.
Ne pas laisser sans surveillance.: Do not leave unattended.
Composter son billet avant l'embarquement.: Validate your ticket before boarding.

The negation gives this use away: ne pas sits together in front, rather than splitting round a conjugated verb.

As a question with no subject

An interrogative word plus an infinitive makes a question that has no subject at all. It reads as deliberation rather than as a request for information.

Que dire ?: What is there to say?
Où aller ?: Where to go?
Pourquoi insister ?: Why insist?

Common in headlines, essays, and interior monologue. It sounds more literary than the equivalent full question.

Infinitive FAQs

What is an infinitive in French?: The unconjugated form of the verb, ending in -er, -ir, -re, or -oir: parler, finir, vendre, voir. It carries no person and no tense, and it is the form you look up in a dictionary and the form the future and conditional are built from.
When do you use à or de before an infinitive?: It depends on the verb in front, not on the infinitive. Commencer, réussir, and apprendre take à: j'ai réussi à finir. Oublier, décider, and refuser take de: elle a décidé de partir. Vouloir, pouvoir, devoir, and aller take nothing at all.
Why does French use the infinitive where English uses -ing?: Because French keeps its -ant form for a narrower job. After a preposition, as a subject, or as the object of another verb, the slot belongs to the infinitive: sans parler, voyager coûte cher, j'aime lire. Only en takes the participle, as in en parlant.
How do you make an infinitive negative in French?: Put ne pas in front of it as a single block: ne pas fumer, il préfère ne pas répondre. The two words stay together, unlike with a conjugated verb where they wrap around it.
Where do object pronouns go with an infinitive?: Immediately before the infinitive, because that is the verb they belong to: je vais te le dire, il faut les acheter. Putting them in front of the conjugated verb, as in je te vais dire, is one of the clearest signs of a learner sentence.