Pouvoir, vouloir, devoir: can, want and must in French

Pouvoir means “can / to be able to”, vouloir means “to want”, and devoir means “must / to have to”. They are the three core modal verbs, they are all irregular, and they share one simple pattern: you conjugate the modal verb for the person, then add a second verb in the infinitive. Je peux venir (“I can come”), je veux venir (“I want to come”), je dois venir (“I have to come”). No preposition goes between them.

Conjugate them in the present

These verbs do not follow the regular endings, so it is worth learning the present tense as a block. Notice that pouvoir and vouloir share the same endings, and that all three change their stem in the plural.

Nous pouvons réserver, mais tu dois confirmer.
We can book, but you have to confirm.

Add an infinitive, with no preposition

The most useful habit is the structure modal + infinitive. Unlike English, French does not add a word like “to” between them — the second verb is simply in its base form.

Je veux apprendre le français. Elle doit travailler ce soir.
I want to learn French. She has to work tonight.

Vouloir and pouvoir can also be followed directly by a noun: je veux un thé (“I want a tea”), tu peux le faire (“you can do it”).

Say it politely: je voudrais, je pourrais

A flat je veux (“I want”) can sound blunt, like a child demanding something. To be polite, French uses the conditional je voudrais (“I would like”) for requests, and je pourrais (“could I”) or tu devrais (“you should”) to soften.

Je voudrais un café, s’il vous plaît. — Tu devrais te reposer.
I would like a coffee, please. — You should rest.

Use je voudrais whenever you order or ask for something; keep je veux for stating a real, strong wish.

Devoir also means “to owe”

One thing to watch: besides “must”, devoir can mean “to owe” when it is followed by an amount or a thing rather than another verb.

Je te dois dix euros.
I owe you ten euros.

Context makes it clear: devoir + infinitive is obligation, devoir + money or an object is debt.

Common mistakes

Adding a preposition before the infinitive

There is no “to” or “à” between the modal and the next verb.

Je peux à venir. / Je veux de partir. → Je peux venir. / Je veux partir.
I can come. / I want to leave.

Using je veux for a polite request

Ordering with je veux sounds demanding. Use the conditional je voudrais.

Je veux un café. → Je voudrais un café, s’il vous plaît.
I would like a coffee, please.

Keeping the singular stem in the plural

The stem changes for nous, vous and ils/elles. Do not say je voule or ils peuvent with the singular stem.

Ils veulent… (said “ils veut”) / Nous pouvons (said “nous peux”) → Ils veulent partir. Nous pouvons aider.
They want to leave. We can help.

When the obligation is a general rule rather than a personal one, French often prefers the impersonal il faut instead of devoir — il faut réserver (“one has to book”) versus je dois réserver (“I have to book”). In Fluera you meet pouvoir, vouloir and devoir inside short, real sentences and hear the irregular forms in context, so the conjugations stop being a list to memorize. Try it when you practice French.

Practice