Promettre is the verb to promise — and one of the highest-frequency verbs of commitment in French. Whatever you pledge, vow, swear, or undertake to do, promettre is the natural verb. Like its cousins permettre and admettre, it is built on mettre and conjugates identically: same consonant drop in the singular (je promets, tu promets, il promet, all /pʁɔ.mɛ/), same restored double t in the plural (nous promettons, vous promettez, ils promettent), same past participle promis. If you can conjugate mettre, you already conjugate promettre.
What makes promettre worth a dedicated reference page is the rich set of constructions it takes — the double-object frame promettre *quelque chose à quelqu'un (promise something to someone), the à + person + *de + infinitif frame for promising to do, the special politeness function of c'est promis and tu me le promets ?, and the reflexive se promettre (promise oneself, vow). It also has a productive idiomatic life: ça promet (that's a sign of things to come / that bodes well or ill), promettre monts et merveilles (promise the moon).
This page covers it all: paradigms, constructions, idioms, and the small but important contrasts with English.
The simple tenses
Identical to mettre — only the prefix pro- is added.
Présent de l'indicatif
Singular forms drop one t in spelling and pronunciation. Plural forms keep the double t.
| Person | Form | Pronunciation |
|---|---|---|
| je | promets | /pʁɔ.mɛ/ |
| tu | promets | /pʁɔ.mɛ/ |
| il / elle / on | promet | /pʁɔ.mɛ/ |
| nous | promettons | /pʁɔ.mɛ.tɔ̃/ |
| vous | promettez | /pʁɔ.mɛ.te/ |
| ils / elles | promettent | /pʁɔ.mɛt/ |
Je te promets que je n'oublierai pas, c'est important pour moi aussi.
I promise you I won't forget — it matters to me too.
Tu promets toujours et tu ne tiens jamais tes promesses.
You always promise and you never keep your promises.
Les politiciens promettent monts et merveilles avant les élections.
Politicians promise the moon before elections.
Imparfait
Plural stem promett- with regular imparfait endings.
| Person | Form |
|---|---|
| je | promettais |
| tu | promettais |
| il / elle / on | promettait |
| nous | promettions |
| vous | promettiez |
| ils / elles | promettaient |
Tu me promettais toujours qu'on partirait en vacances ensemble, et puis voilà.
You always used to promise we'd go on vacation together — and look how that turned out.
On nous promettait des augmentations chaque année, mais rien n'arrivait jamais.
They kept promising us raises every year, but nothing ever came.
Passé simple (literary)
| Person | Form |
|---|---|
| je | promis |
| tu | promis |
| il / elle / on | promit |
| nous | promîmes |
| vous | promîtes |
| ils / elles | promirent |
Il lui promit fidélité jusqu'à la mort. (literary)
He promised her fidelity unto death.
Futur simple
| Person | Form |
|---|---|
| je | promettrai |
| tu | promettras |
| il / elle / on | promettra |
| nous | promettrons |
| vous | promettrez |
| ils / elles | promettront |
Je te promettrai tout ce que tu veux, mais arrête de pleurer.
I'll promise you anything you want, just stop crying.
On lui promettra une augmentation à condition qu'il reste un an de plus.
We'll promise him a raise on condition that he stays another year.
Conditionnel présent
| Person | Form |
|---|---|
| je | promettrais |
| tu | promettrais |
| il / elle / on | promettrait |
| nous | promettrions |
| vous | promettriez |
| ils / elles | promettraient |
Tu me promettrais n'importe quoi pour avoir ce que tu veux.
You'd promise me anything to get what you want.
Subjonctif présent
| Person | Form |
|---|---|
| (que) je | promette |
| (que) tu | promettes |
| (qu')il / elle / on | promette |
| (que) nous | promettions |
| (que) vous | promettiez |
| (qu')ils / elles | promettent |
Il faut que tu me promettes de faire attention sur la route.
You have to promise me you'll be careful on the road.
Impératif
| Person | Form |
|---|---|
| (tu) | promets |
| (nous) | promettons |
| (vous) | promettez |
Promets-moi que tu m'appelleras dès que tu arrives.
Promise me you'll call me the moment you get there.
Promettez de ne rien dire à personne.
Promise not to say anything to anyone.
Participles and gérondif
- Participe passé: promis (feminine promise, plural promis / promises)
- Participe présent: promettant
- Gérondif: en promettant
The feminine participle promise is also a standalone noun: la promise (the betrothed, the bride-to-be) and un promis (the betrothed groom) — slightly archaic but still recognized in literary register.
En promettant la lune, on déçoit forcément.
When you promise the moon, you're sure to disappoint.
La récompense promise n'est jamais arrivée.
The promised reward never came.
The compound tenses
Promettre uses avoir as its auxiliary in all compound tenses. The reflexive se promettre uses être.
Passé composé
avoir (présent) + promis
Tu m'avais promis de ne plus jamais recommencer.
You'd promised me never to do it again.
Je lui ai promis qu'on irait à la plage dimanche.
I promised him we'd go to the beach on Sunday.
On nous a promis monts et merveilles, et au final on n'a rien eu.
They promised us the moon and we ended up with nothing.
The participle agrees with a preceding direct object — though in the standard promettre à X de + inf frame, the de-clause is not a direct object, so agreement does not arise. It does arise when the thing promised is a direct-object noun moved before the participle:
La récompense que tu m'as promise, je l'attends toujours.
The reward you promised me — I'm still waiting for it. (Agreement: la récompense, f.sg., is the preceding direct object, so promise becomes promise.)
Plus-que-parfait, futur antérieur, conditionnel passé
The other compound tenses follow the standard pattern.
Si tu me l'avais promis plus tôt, j'aurais pu m'organiser.
If you'd promised me earlier, I could have planned.
J'aurais promis n'importe quoi à ce moment-là, j'étais désespéré.
I'd have promised anything at that moment — I was desperate.
The core uses
1. Promettre quelque chose à quelqu'un — to promise something to someone
The double-object construction. The thing promised is a direct object; the person is an indirect object (à + person, or an indirect-object pronoun me, te, lui, nous, vous, leur).
promettre + DO + à + person
Mon père m'a promis une voiture pour mon dix-huitième anniversaire.
My father promised me a car for my eighteenth birthday.
On lui a promis une promotion l'année prochaine.
They promised her a promotion next year.
Tu m'as promis ce livre depuis trois mois, je l'attends toujours.
You promised me that book three months ago — I'm still waiting.
2. Promettre à quelqu'un de + infinitif — to promise someone to do
This is the construction for promising to do something. The person is à-marked, the action is introduced by de + infinitif. The subject of the promise and the subject of the action are the same person — coreferential.
promettre *à quelqu'un de + infinitif*
Je te promets de t'écrire toutes les semaines.
I promise you I'll write to you every week.
Promets-moi de ne pas faire de bêtises pendant que je suis partie.
Promise me you won't do anything stupid while I'm gone.
Il a promis à ses parents de rentrer avant minuit.
He promised his parents he'd be home before midnight.
When the person is a pronoun, it cliticizes onto the verb (me, te, lui, nous, vous, leur), and de + infinitif stays put:
Je vous promets de tout faire pour que ça se passe bien.
I promise you I'll do everything to make this go well.
3. Promettre que + indicative — to promise that…
When the subject of the promise is not the same as the subject of the promised action, French uses promettre que + indicative (not subjunctive! — see below). The verb in the que-clause is most often in the futur or futur proche, since promises are about the future.
promettre que + future-tense clause
Je te promets qu'on ira à Disneyland cet été, c'est juré.
I promise you we'll go to Disneyland this summer — I swear.
Le maire a promis que les travaux seraient terminés en juin.
The mayor promised that the construction would be finished in June.
Promets-moi que tu seras prudent.
Promise me you'll be careful.
Why indicative, not subjunctive? Promettre expresses a strong commitment that the action will happen — the speaker presents the future event as essentially factual, not as a wish or possibility. This contrasts with vouloir que or souhaiter que, which mark the action as desired but not guaranteed. In negative or interrogative form, however, the certainty is undermined and the subjunctive becomes possible: je ne promets pas qu'il vienne (I don't promise he'll come).
4. C'est promis — it's a promise
A fixed phrase, used standalone or as a tag. C'est promis (it's a promise / I promise) is one of the most-used reassurance phrases in French, especially with children and intimates.
Je rangerai ma chambre demain, c'est promis.
I'll clean my room tomorrow — I promise.
On ne le dira à personne, c'est promis-juré.
We won't tell anyone — promise-swear. (children's intensifier)
Tu rentres avant onze heures ? — Oui, c'est promis.
Are you home by eleven? — Yes, I promise.
The intensifier promis-juré is informal and mostly used by or with children, but adults use it too in light-hearted reassurance.
5. Tu me le promets ? — Do you promise me?
A standard question form for asking someone to confirm a promise. The pronoun le picks up the previous statement (whatever was just said). With formal vous: Vous me le promettez ?
Tu ne lui diras rien ? — Non, je ne dirai rien. — Tu me le promets ?
You won't tell him anything? — No, I won't say a word. — Do you promise me?
Vous me promettez de me rappeler dès que vous avez les résultats ?
Do you promise to call me back as soon as you have the results?
6. Se promettre (de) — to promise oneself, to vow
The reflexive se promettre is "to promise oneself" — used for personal vows, resolutions, intentions. It uses être in compound tenses.
Je me suis promis de ne plus jamais boire le dimanche soir.
I promised myself I'd never drink on Sunday nights again.
On s'est promis de se revoir tous les ans, mais le temps passe vite.
We promised ourselves we'd see each other every year — but time flies.
Elle s'était promis de ne plus jamais lui parler, et pourtant elle l'a appelé.
She'd vowed never to speak to him again, and yet she called him.
The reciprocal reading is also available: on s'est promis can mean we promised each other (with each other as the recipients of the promise).
High-frequency idioms
- c'est promis (-juré) — it's a promise (-swear)
- tu me le promets ? — do you promise?
- promettre la lune / promettre monts et merveilles — to promise the moon
- ça promet ! — that bodes well or ill (sarcastic — said of a situation that looks like trouble)
- un avenir prometteur (related adjective) — a promising future
- terre promise — promised land
- tenir sa promesse / sa parole — to keep one's promise / one's word
- ne pas tenir parole — to break one's word
Le premier jour de stage, mon chef est arrivé en colère. Ça promet, je me suis dit.
On my first day as an intern, my boss showed up angry. 'This bodes well,' I thought to myself. (sarcastic)
Cet enfant a un avenir prometteur dans le tennis, c'est sûr.
That child has a promising future in tennis — that's for sure.
Tu m'as promis et tu n'as pas tenu parole.
You promised me and you didn't keep your word.
Comparison with English
Three friction points worth flagging:
- The à
- de split (again).
- Indicative, not subjunctive, after promettre que. Many learners over-apply the subjunctive, hearing promettre as a verb of will. But promettre expresses confident commitment — the speaker is presenting the future event as guaranteed — so the indicative is correct. Je te promets qu'il viendra (I promise you he'll come), not qu'il vienne.
- No promise
- bare infinitive without à.
Common Mistakes
Mistake 1: Forgetting de before the infinitive.
❌ Je te promets venir demain.
Wrong — promettre always takes de before the infinitive: je te promets DE venir.
✅ Je te promets de venir demain.
I promise you I'll come tomorrow.
Mistake 2: Using subjunctive after affirmative promettre que.
❌ Je te promets qu'il vienne demain.
Wrong — affirmative promettre que takes the indicative because the speaker is asserting the future event as guaranteed.
✅ Je te promets qu'il viendra demain.
I promise you he'll come tomorrow.
Mistake 3: Using a direct object for the person.
❌ Je promets ma fille un cadeau.
Wrong — the person is the indirect object: je promets un cadeau À ma fille.
✅ Je promets un cadeau à ma fille. / Je lui promets un cadeau.
I'm promising my daughter a gift.
Mistake 4: Misordering arguments with pronouns.
❌ Je promets toi de venir.
Wrong — disjunctive toi cannot replace an indirect object pronoun. Use the clitic te before the verb.
✅ Je te promets de venir.
I promise you I'll come.
Mistake 5: Confusing promettre with engager / jurer in fixed phrases.
❌ Je te promets sur l'honneur.
Stilted — for swearing on one's honor, French prefers je te jure sur l'honneur (with jurer). Promettre is for committing to a future action, not for swearing oaths of truth about a past or present fact.
✅ Je te jure sur l'honneur que c'est vrai. / Je te promets de t'aider.
I swear on my honor it's true. / I promise to help you.
Key takeaways
Promettre conjugates exactly like mettre: singular consonant drop in the present (je promets, tu promets, il promet), restored double t in the plural (nous promettons, vous promettez, ils promettent), past participle promis. It uses avoir in compound tenses; the reflexive se promettre uses être.
Three core constructions: promettre + DO + à + person (promise something to someone — je lui ai promis une voiture); promettre *à + person + de + infinitif (promise someone to do — *je te promets de venir); promettre que + indicative (promise that — je te promets qu'on ira à Disneyland). The indicative after promettre que is the rule, not the exception — promettre presents the future event as guaranteed.
The reflexive se promettre de is for personal vows and resolutions (je me suis promis d'arrêter de fumer). The standalone c'est promis is one of the most-used reassurance phrases in everyday French. And ça promet ! — uttered with a sigh — is the perfect French sarcastic comment when something looks like trouble.
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Start learning French→Related Topics
- Mettre: Full Verb ReferenceA1 — Mettre is the everyday verb for putting, placing, and putting on — but it also means to take time, to turn on, and (reflexively) to start. This page is the full reference: every paradigm, the core uses, the major idioms, and the family of compounds (permettre, promettre, admettre, soumettre, transmettre).
- Permettre: Full Verb ReferenceA2 — Permettre is the verb to allow, permit — and it conjugates identically to mettre. Its signature construction is permettre à quelqu'un de + infinitif (allow someone to do something), and it triggers the subjunctive after permettre que. This page is the full reference: every paradigm, the core uses, the high-frequency idioms (vous permettez ?, ça me permet de…, se permettre de…), and the small but crucial syntactic traps.
- Admettre: Full Verb ReferenceB1 — Admettre is the verb to admit, accept, acknowledge — and one of the most polarity-sensitive verbs in French. In affirmative form, admettre que takes the indicative (the speaker accepts the proposition as fact). In interrogative or negative form, it takes the subjunctive (the speaker is questioning whether the proposition holds). The set phrase en admettant que also requires the subjunctive. Conjugates exactly like mettre. Past participle: admis.
- De vs À with Verbs Before an InfinitiveA2 — When one French verb is followed by another in the infinitive, the link between them is either nothing, the preposition de, or the preposition à. The choice is largely arbitrary and must be memorised verb by verb — but there are patterns and tendencies that make the lists learnable.
- Subjunctive after Verbs of Desire and VolitionB1 — When you want, prefer, wish, demand, or expect someone else to do something, French uses the subjunctive — and when the wanter and the doer are the same person, French collapses the construction to a plain infinitive.