The four core French modals — pouvoir, vouloir, devoir, savoir — do for French what can, want, must, and know how to do for English. They sit between the subject and the main verb, modify the speaker's stance toward the action, and combine with a bare infinitive to build expressions like je peux le faire (I can do it), je veux partir (I want to leave), je dois travailler (I have to work), je sais nager (I know how to swim).
This page surveys all four together so you can see the system at a glance: how they conjugate, how they combine with an infinitive, what each one actually means (with the meaning ranges that English's "can" and "must" obscure), how the conditional softens them into politeness markers, and how to handle them in compound tenses. For full conjugations and idiomatic uses, see the dedicated pages on each verb: pouvoir, vouloir, devoir, savoir.
The four modals at a glance
| Verb | Core meaning | Translation | Example |
|---|---|---|---|
| pouvoir | physical possibility, ability, permission | can, may, be able to | Je peux venir. |
| vouloir | desire, will | want, would like | Je veux partir. |
| devoir | obligation, probability, debt | must, have to, ought to, owe | Je dois travailler. |
| savoir | mental ability, knowing how | know how to, can | Je sais nager. |
Conjugations in the present
All four are irregular and must be memorized. They share two structural features: a vowel-changing stem and idiosyncratic 1pl / 2pl forms.
| Person | pouvoir | vouloir | devoir | savoir |
|---|---|---|---|---|
| je | peux | veux | dois | sais |
| tu | peux | veux | dois | sais |
| il / elle / on | peut | veut | doit | sait |
| nous | pouvons | voulons | devons | savons |
| vous | pouvez | voulez | devez | savez |
| ils / elles | peuvent | veulent | doivent | savent |
A few quirks worth flagging:
- Je peux and tu peux are homophones — both /pø/. The same is true of je veux / tu veux /vø/ and je dois / tu dois /dwa/.
- Pouvoir has an archaic alternative je puis ("I can"), still found in formal inversion: Puis-je vous aider ? (May I help you?). In modern French, this is the only place puis survives.
- Savoir in 1sg is je sais /sɛ/, not je sai — the -s is mandatory in spelling.
- The 1pl / 2pl stems differ from the singular: pouv-, voul-, dev-, sav-, with vowel changes. Je peux but nous pouvons; je dois but nous devons.
The construction: modal + bare infinitive
All four modals combine with a bare infinitive — no preposition in between. This is the same pattern as English (I can leave, I want to leave, I must leave, I know how to swim), except that English requires "to" before the infinitive in three of the four cases (and "how to" in the fourth). French requires nothing.
Je peux le faire moi-même, ne t'inquiète pas.
I can do it myself — don't worry.
Tu veux partir tout de suite ou on attend encore un peu ?
Do you want to leave right away, or do we wait a bit longer?
On doit rentrer avant minuit, sinon les parents s'inquiètent.
We have to be back before midnight, otherwise our parents will worry.
Elle sait conduire mais elle préfère prendre le métro.
She knows how to drive, but she prefers taking the metro.
The structure is rigid. Je peux à le faire, je veux de partir, je dois pour travailler are all wrong — no preposition can intrude between the modal and the infinitive.
Pouvoir vs savoir: the great trap for English speakers
English collapses two distinct French concepts into one word: can.
- I can swim. (= I have the physical ability)
- I can swim. (= I know how to swim, I have learned)
French separates these:
- Je peux nager. — I am physically able to swim right now (I'm not too tired, the pool is open, I'm not injured).
- Je sais nager. — I know how to swim (I learned, the skill is acquired and stable).
The distinction is acquired skill (savoir) vs current ability (pouvoir). Anything you have learned — driving, swimming, playing piano, speaking a language, using a tool — falls under savoir. Anything that depends on the current circumstances — whether you have time, whether you are physically able, whether you have permission — falls under pouvoir.
Je sais conduire, mais je ne peux pas conduire ce soir parce que j'ai bu.
I know how to drive, but I can't drive tonight because I've been drinking.
This sentence shows the distinction in stark relief: the speaker has the acquired skill (savoir), but circumstance prevents the current exercise of that skill (pouvoir).
Tu sais nager ? — Oui, j'ai appris quand j'étais petit.
Do you know how to swim? — Yes, I learned when I was little.
Je ne peux pas nager aujourd'hui, j'ai mal à l'épaule.
I can't swim today — my shoulder hurts.
In Spanish, the same split exists (saber vs poder). English is the outlier: a single "can" that has to do double duty.
The three meanings of devoir
Devoir is the most semantically loaded of the four modals. It carries three distinct meanings, distinguished only by context:
1. Obligation: must, have to
Je dois finir ce rapport avant lundi.
I have to finish this report before Monday.
Tu dois prendre tes médicaments tous les matins.
You have to take your medication every morning.
2. Probability / Inference: must (epistemic)
Il doit être au moins minuit, je suis épuisé.
It must be at least midnight — I'm exhausted.
Marie doit être à Paris en ce moment, je l'ai vue partir hier.
Marie must be in Paris right now — I saw her leave yesterday.
3. Owing: to owe
In this third sense, devoir takes a direct object (a sum, an apology, a favour) rather than an infinitive:
Tu me dois cinquante euros depuis le mois dernier.
You owe me fifty euros from last month.
On doit beaucoup à nos parents.
We owe our parents a lot.
The three meanings share the same conjugation but are completely separate semantically. Context — and the presence or absence of a following infinitive — disambiguates which one is meant.
The conditional: politeness magic
Putting pouvoir, vouloir, devoir (and savoir to a lesser extent) into the conditional softens them dramatically — the way English shifts from "want" to "would like" or from "can you" to "could you."
| Direct (present) | Soft (conditional) | English |
|---|---|---|
| je veux | je voudrais | I want → I would like |
| tu peux | tu pourrais | you can → you could |
| vous devez | vous devriez | you must → you should |
| tu sais | tu saurais | you know → you'd know (how to) |
In a French restaurant, you almost never order with je veux — that sounds like a child demanding. You use je voudrais or, even softer, je vais prendre. With strangers, pouvez-vous is workable but pourriez-vous is more polite. The conditional is non-negotiable in customer-service interactions and any situation where you want to be tactful.
Je voudrais une baguette et deux croissants, s'il vous plaît.
I'd like a baguette and two croissants, please.
Pourriez-vous m'indiquer la rue de Rivoli ?
Could you tell me where rue de Rivoli is?
Tu devrais te reposer un peu, tu as l'air fatigué.
You should rest a little — you look tired.
Je saurais répondre à cette question si j'avais le temps de réfléchir.
I would be able to answer that question if I had time to think it over.
The compound tenses: all four take avoir
In the passé composé and other compound tenses, all four modals take avoir as the auxiliary. The past participles are:
- pouvoir → pu /py/
- vouloir → voulu /vuly/
- devoir → dû /dy/ (with an obligatory circumflex on the u in the masculine singular only — see below)
- savoir → su /sy/
Je n'ai pas pu venir hier, j'avais une réunion.
I couldn't come yesterday — I had a meeting.
Elle a voulu partir tôt mais le train était bloqué.
She wanted to leave early but the train was stuck.
On a dû annuler le pique-nique à cause de la pluie.
We had to cancel the picnic because of the rain.
Tu as su quoi répondre ? Moi, j'étais perdu.
Did you know what to answer? I was lost.
A note on dû: the circumflex distinguishes the past participle of devoir from the contracted preposition du (= de + le). The circumflex appears on the masculine singular only; the other agreement forms drop it.
- dû (m.sg., with circumflex): Le respect qui lui est dû. (the respect owed to him)
- due (f.sg., no circumflex): La somme qui lui est due. (the sum owed to him)
- dus (m.pl.) / dues (f.pl., no circumflex): Les efforts qui leur sont dus.
In compound tenses like J'ai dû partir / Elle a dû partir, the participle stays dû (invariable, with circumflex) because it is followed by an infinitive — there is no preceding direct object to trigger agreement. The feminine and plural forms appear only when dû is used as a true adjective or with a preceding direct object referring to a thing owed.
Compound tenses with modals shift the meaning subtly. J'ai pu le faire means "I managed to do it" (the action was accomplished, against possible obstacles), not "I had the ability to do it." For sustained ability in the past, French uses the imparfait: je pouvais le faire (I was able to / could do it, generally).
Je pouvais courir 10 km à 18 ans, mais je n'ai pas pu finir ma course hier.
I was able to run 10 km at 18, but I couldn't finish my race yesterday.
This contrast between pu (specific accomplishment) and pouvais (general ability) is one of the trickiest aspects of past tense in French — a side effect of the imparfait/passé composé split that does not exist in English.
Modals are not auxiliaries
In some traditions, "modal verb" suggests a verb that triggers special rules (English modals do not take do in questions, do not take -s in 3sg, etc.). French modals are not auxiliaries: they take avoir in compound tenses, conjugate fully across all persons and tenses, and take pronouns like ordinary verbs. The only thing that distinguishes them syntactically is the bare infinitive complement — and many other French verbs share that pattern. The category "modal" in French is more semantic than syntactic.
Pronoun position with modals
When the embedded infinitive has an object pronoun, the pronoun attaches to the infinitive, not to the modal. This is the standard rule for verb + infinitive:
Je veux le voir avant qu'il parte.
I want to see him before he leaves.
Tu peux me passer le sel ?
Can you pass me the salt?
On doit les prévenir tout de suite.
We have to warn them right away.
Elle sait le faire mieux que personne.
She knows how to do it better than anyone.
Negation wraps the modal: je ne peux pas le faire, je ne veux pas le voir. The pronoun stays with the infinitive.
Sample dialogue
— Tu peux venir samedi soir ? On organise un dîner. — Je voudrais bien, mais je dois travailler dimanche matin. Je ne sais pas si je peux rester tard.
— Can you come Saturday night? We're having a dinner. — I'd really like to, but I have to work Sunday morning. I don't know if I can stay late.
— Pourriez-vous m'aider à porter ces sacs ? — Bien sûr, donnez-moi le plus lourd.
— Could you help me carry these bags? — Of course, give me the heaviest one.
Common Mistakes
Mistake 1: Confusing pouvoir and savoir.
❌ Je peux nager depuis l'âge de cinq ans.
Wrong meaning — for an acquired skill, use savoir. Pouvoir would imply current physical ability.
✅ Je sais nager depuis l'âge de cinq ans.
I've known how to swim since I was five.
Mistake 2: Inserting à or de between the modal and the infinitive.
❌ Je veux de partir. / Je peux à le faire.
No preposition belongs between a modal and the bare infinitive.
✅ Je veux partir. / Je peux le faire.
I want to leave. / I can do it.
Mistake 3: Using je veux in a polite request.
❌ Je veux un café, s'il vous plaît.
Sounds brusque, even rude. In customer-service French, the conditional is mandatory.
✅ Je voudrais un café, s'il vous plaît.
I'd like a coffee, please.
Mistake 4: Forgetting the circumflex on dû (m.sg. of devoir).
❌ J'ai du partir tôt.
Without the circumflex, du looks like the contracted preposition. The participle of devoir is dû in m.sg.
✅ J'ai dû partir tôt.
I had to leave early.
Mistake 5: Putting the pronoun before the modal instead of the infinitive.
❌ Je le veux faire.
Wrong — the pronoun attaches to the infinitive (the verb whose object it is).
✅ Je veux le faire.
I want to do it.
Mistake 6: Confusing the obligation and probability senses of devoir.
❌ Hearing 'Marie doit être à Paris' as a command.
In context, this is most likely the probability reading — 'Marie must be in Paris' (inference). Only the verb's complement and context distinguish obligation from probability.
✅ Marie doit être à Paris. = Marie must be in Paris (probably is). vs Marie doit aller à Paris. = Marie has to go to Paris.
Probability vs obligation — context tells you which.
Mistake 7: Using pu when you mean general past ability.
❌ Je n'ai pas pu courir vite quand j'étais jeune.
The passé composé suggests one specific failed attempt, not general past ability. For ongoing ability in the past, use the imparfait.
✅ Je ne pouvais pas courir vite quand j'étais jeune.
I couldn't run fast when I was young. (general past ability)
Key takeaways
Three points to internalize:
The construction is identical for all four: modal (conjugated) + bare infinitive (no preposition). Je peux le faire, je veux partir, je dois travailler, je sais nager.
Pouvoir and savoir are not interchangeable. Pouvoir = current ability or permission. Savoir = acquired skill. Je sais conduire mais je ne peux pas conduire ce soir.
The conditional is the politeness lever. Je voudrais, tu pourrais, vous devriez — these are the daily-life forms. Reserve the bare present for direct, unsoftened statements with people you know well; in any neutral or polite context, switch to the conditional.
For deeper coverage of each verb's full paradigm, idioms, and edge cases, study the dedicated pages: pouvoir, vouloir, devoir, savoir.
Now practice French
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning French→Related Topics
- Le Présent: Pouvoir (can / be able to)A1 — The full paradigm of pouvoir — French's main modal verb for ability, possibility, permission, and polite request — including the formal alternative je puis, the conditional je pourrais for politeness, and why French has no one-word equivalent for 'could'.
- Le Présent: Vouloir (to want)A1 — The full paradigm of vouloir — French's verb for wanting and willing — with the bluntness of je veux, the politeness of je voudrais, the subjunctive after vouloir que, and the formal imperative veuillez.
- Le Présent: Devoir (must / have to / owe)A1 — The full paradigm of devoir — French's verb for obligation, probability, and debt — with the conditional je devrais for advice, the contrast with impersonal il faut, and why French uses the same word for 'must do' and 'must be true'.
- Le Présent: Savoir (to know)A1 — The full paradigm of savoir, the French verb for knowing facts, knowing how to do something, and possessing information — and the crucial line that separates it from connaître.
- Le Conditionnel: Overview of the French Conditional MoodA2 — The conditionnel is more than 'would' — it's the polite voice, the hypothetical voice, the future-in-the-past, and the journalistic hedge. One paradigm, six everyday jobs, and a place at the heart of grown-up French.
- L'Infinitif: OverviewA2 — The French infinitive is the bare verb form (parler, finir, vendre, faire). It is the dictionary entry, the most syntactically flexible form of the verb, and the form English speakers most often misuse — usually because they reach for the '-ing' form where French wants the bare infinitive.