Les Verbes Modaux: Overview of French Modal Verbs

A modal verb in French is a verb that combines with a following infinitive to add a layer of meaning — possibility, permission, desire, obligation, knowledge — to the action named by the infinitive. The four core modals are pouvoir (can / be able to / may), vouloir (want), devoir (must / have to / should), and savoir (know how to). Each takes a bare infinitive with no preposition: je peux venir, je veux venir, je dois venir, je sais nager. None of them takes à or de before the infinitive in their modal use, which is what distinguishes them syntactically from the dozens of other verbs that take an infinitive complement (j'ai décidé de partir, je commence à comprendre).

This page is the index. It introduces each modal verb's core meaning, shows the basic syntactic frame, walks through the polite uses of the conditionnel that every adult speaker reaches for daily, and previews the irregular conjugations that each detail page treats in full. By the end you should know which modal to pick for which idea, and how to recognize the signature politeness shifts (je voudrais, pourriez-vous, tu devrais, j'aurais dû) that make French sound French.

The four core modal verbs

Below the four core verbs sits a smaller cluster: falloir (impersonal must, used only in il faut), aimer (in conditionnel = "would like"), and a handful of verbs that behave modally in restricted contexts. Each detail page covers its own irregularities; this overview gives you the system.

The bare-infinitive frame

The single most important syntactic fact about French modals is the absence of a preposition between the modal and the infinitive that follows.

[Modal conjugated for subject and tense] + [bare infinitive of the lexical verb]

No à, no de, no que, no to. This trips up English-speaking learners because English want takes to before its infinitive (I want to come), and it trips up Spanish-speaking learners who carry over tener que (have to + que). In French the two verbs sit side by side with nothing between them.

Pouvoir vs savoir: the can-can split

The pair pouvoir and savoir both translate as English can — and learners who don't notice the split end up choosing the wrong one. The distinction is real and matters.

pouvoir = current ability or possibility — circumstances allow it now.

savoir = acquired skill or learned knowledge — I have internalized how to do this.

A useful diagnostic: if you can substitute "know how to" for "can" in English without changing the meaning, the French is savoir. If you can substitute "be able to / be allowed to," the French is pouvoir. I know how to swim (savoir) is permanent; I can swim today (pouvoir) depends on circumstances.

The trickiest case is current physical capacity. I can run ten kilometers in the sense "my body is able to do this right now" is je peux courir dix kilomètres. I can run the marathon meaning "I have the training" is je sais courir un marathon — though many speakers blur this in colloquial use. When in doubt, use pouvoir; savoir + infinitive is the marked option for true skill.

See pouvoir-detail and savoir-detail for the full treatment.

Devoir: must, should, owe, supposed to

Devoir is the most semantically loaded modal. It does the work that English splits across must, have to, should, ought to, owe, be supposed to. The reading depends on tense and context.

Three of these readings — obligation, inference, schedule — share the same surface form (il doit + infinitif). Context disambiguates. Il doit travailler could mean "he has to work" (his contract requires it), "he must be working" (I infer because his light is on), or "he is supposed to be working" (according to the schedule). Spoken delivery — emphasis, intonation, surrounding clauses — usually makes the reading clear.

See devoir-detail for the full conjugation and the conditionnel uses.

The conditionnel makes them polite

The single most useful pattern across all the modals is the conditionnel for politeness. Putting a modal into the conditionnel softens its force and is the default register for adult interaction in shops, offices, and conversations between equals.

The shift in register is significant. Je veux un café sounds blunt — almost rude — when ordering at a café. Je voudrais un café, s'il vous plaît is the polite default. Tu dois te reposer sounds like a command from someone with authority over you; tu devrais te reposer is friendly advice between equals.

For the full conditionnel-as-politeness treatment, see voudrais-pourrais-politeness and devrais-should.

The conditionnel passé means regret

Putting a modal into the conditionnel passé — aurais + dû / pu / voulu + infinitive — produces the regret/reproach reading: "I should have / could have / would have wanted to."

This three-way modal triplet — aurais dû (should have), aurais pu (could have), aurais voulu (would have wanted) — is one of the highest-payoff structures to internalize. It is the engine of regret and reproach in French and recurs constantly in conversation. See conditionnel-passe-regret.

Modals are highly irregular

Each modal has an irregular present indicative, an irregular futur stem, and (for vouloir and pouvoir) an irregular subjunctive stem. The good news: the same irregularities recur in the same places, so once you have pouvoir you have a template for vouloir.

Notice the pattern: each verb has a stem-vowel alternation between the strong forms (peux/peut/peuvent, veux/veut/veulent, dois/doit/doivent) and the weak forms (pouvons, voulons, devons). The futur stem is unpredictable and must be memorized: pourr-, voudr-, devr-, saur-. The subjunctive often has its own stem (puiss-, veuill-, sach-). The participe passé dû takes a circumflex in the masculine singular (to disambiguate from the partitive du), and drops it in the feminine and plural: due, dus, dues.

Each detail page drills the full paradigm. The take-away here: do not try to "regularize" any of these. Memorize them as a set.

Asking and negating with modals: French has no auxiliary do

A point that English speakers stumble on: French has no auxiliary "do" for questions or negations. Where English uses do you want, did you want, didn't you want, French uses inversion of the modal itself or est-ce que + the modal.

The modal itself moves to form the question; nothing is added the way English adds do. This is the rule for every verb in French, but it is most visible with modals because modals are where English do-support is most obvious.

Modal + que + subjunctive: when subjects differ

When the modal verb's subject is the same as the action's subject, you use the infinitive: je veux partir (I want to leave — both subjects are I). When the modal's subject is different from the action's subject, French requires que + the subjunctive: je veux qu'il parte (I want him to leave — I want, he leaves).

This is the trickiest single point for English speakers. English uses want him to, would like you to — a single construction that ignores subject difference. French does not allow this: the infinitive only works when the subjects match; otherwise que + subjunctive is mandatory. See verbs/subjunctive/triggers/desire-volition.

Falloir: the impersonal must

falloir is a defective verb that exists only in the third-person singular impersonal form il faut. It expresses general necessity — one must, it is necessary. It can be followed by an infinitive or by que + subjunctive.

Il faut is more general than je dois: it expresses a necessity from the situation rather than a personal obligation. Je dois travailler (I have to work — my obligation); il faut travailler (one has to work — general truth or impersonal necessity). For full coverage see falloir-as-quasi-modal.

Common Mistakes

Mistake 1: Inserting a preposition between a modal and its infinitive.

Mistake 2: Using savoir for current ability or pouvoir for skill.

Mistake 3: Using the infinitive when subjects differ instead of que + subjunctive.

Mistake 4: Using the indicative je veux / tu peux / tu dois in polite registers.

Mistake 5: Forgetting the circumflex on dû (the past participle of devoir).

Mistake 6: Adding do/does/did in questions.

Key takeaways

The four core French modals — pouvoir, vouloir, devoir, savoir — take a bare infinitive with no preposition. Each has a distinct semantic territory: ability/permission/possibility (pouvoir), desire/willingness (vouloir), obligation/probability/recommendation (devoir), acquired skill (savoir). The pair pouvoir and savoir both translate as English can; the split is between current ability/permission (pouvoir) and learned skill (savoir).

The conditionnel of every modal softens it for politeness — je voudrais (I would like), pourriez-vous (could you), tu devrais (you should), sauriez-vous (would you happen to know). The conditionnel passé builds the regret/reproach triplet aurais dû / aurais pu / aurais voulu (should have / could have / would have wanted to). When subjects differ, modals trigger que + subjunctive (je veux qu'il vienne); when subjects match, the infinitive does the job (je veux venir). All modals are highly irregular and must be memorized; each detail page drills the full paradigm.