What this is
English has a small set of words — can, want, must — that sit in front of another verb without ever needing “to.” French has the same idea, but they’re full verbs with their own irregular conjugations: pouvoir (can / to be able to), vouloir (to want), devoir (must / to have to). Learn these three and you can suddenly say what you’re able to do, what you want to do, and what you’re supposed to do — which covers an enormous share of ordinary conversation.
The rule
All three drop the infinitive ending and build a present tense that changes its stem partway through the paradigm — a shape called the “boot,” because if you draw a line around the forms that share one stem (je, tu, il, ils) it traces something boot-shaped on the page, leaving nous and vous outside it with a second stem.
| pouvoir | vouloir | devoir | |
|---|---|---|---|
| je | peux | veux | dois |
| tu | peux | veux | dois |
| il/elle/on | peut | veut | doit |
| nous | pouvons | voulons | devons |
| vous | pouvez | voulez | devez |
| ils/elles | peuvent | veulent | doivent |
Read across a row and the three verbs rhyme: peux/veux/dois, peut/veut/doit, peuvent/veulent/doivent. Once you have pouvoir’s pattern, vouloir is nearly free, and devoir just swaps in its own vowel.
Each one goes directly in front of an infinitive, with nothing between them:
- Je peux finir mon travail maintenant. — I can finish my work now.
- Je veux danser avec toi. — I want to dance with you.
- Je dois étudier maintenant. — I have to study now.
No “to,” no “de,” no “à” — the two verbs just sit next to each other.
Why it works this way
The boot pattern isn’t random: the singular and third-person-plural forms share a stem built for a single, closed syllable (peu-, veu-, doi-), while nous and vous need a stem that can carry the -ons/-ez endings smoothly, so they fall back to a longer, more “regular-looking” stem (pouv-, voul-, dev-) that the singular forms would sound clumsy with. This same split — one stem for je/tu/il/ils, another for nous/vous — shows up across a wide swath of irregular French verbs, so recognizing the shape here is a pattern you’ll meet again.
The “no preposition” rule for the infinitive isn’t arbitrary either: pouvoir, vouloir, and devoir behave as auxiliary-like verbs here, similar to how “will” or “can” work in English without “to.” French marks that closeness by putting nothing between them at all.
Edge cases
The shared skeleton
pouvoir and vouloir don’t just rhyme by coincidence — they share the exact same person-by-person shape (peux/veux, peux/veux, peut/veut, pouvons/voulons, pouvez/voulez, peuvent/veulent), and devoir tracks the same shape with its own vowel (dois, dois, doit, devons, devez, doivent). If you can conjugate one, you can conjugate all three by ear — the risk is the opposite problem, mixing up which verb a given form belongs to when they all sound similar in a fast sentence.
je voudrais, the polite exception
Plain je veux (“I want”) is grammatically correct but reads as blunt in most everyday requests — the same way “I want a coffee” sounds more like a demand than a customer’s request in English. French sidesteps this with je voudrais (“I would like”), technically a conditional form of vouloir that hasn’t been taught as a tense yet, but worth learning right now as a fixed, memorized phrase: Je voudrais un café. It’s the version of “I want” that a stranger, a waiter, or a shopkeeper expects to hear.
What English speakers get wrong here
The most common slip is inserting a preposition where French has none: reaching for “je peux de sortir” or “je veux à danser” by analogy with English phrasal patterns or with other French verbs that do take de or à before an infinitive (like finir de or réussir à, from the -ir verbs). Pouvoir, vouloir, and devoir take the bare infinitive, full stop.
The second is confusing devoir’s two separate jobs. Followed by an infinitive, it means obligation — je dois partir (I have to leave). Followed directly by a noun, it switches to meaning “owe” — je dois vingt euros à mon frère (I owe my brother twenty euros). Same verb, same conjugation, genuinely different meaning depending on what comes after it — there’s no way to tell which sense is meant except by looking at what follows.
The third is treating je veux and je voudrais as interchangeable. They conjugate from the same verb but land very differently in a real conversation — save veux for describing what you want in the abstract, and reach for voudrais the moment you’re actually asking someone for something.