How to Say I Don't Know in French: Je Ne Sais Pas

Someone asks you a question in French, your mind goes blank, and out pops "Je no know". It happens to every learner. Knowing how to say I don't know in French is one of the most useful survival skills you can have, because it buys you time and keeps the conversation friendly.

Why "I Don't Know" Is Trickier Than It Looks

On the surface it's three words: je ne sais pas. But French has several ways to say it, and the right one depends on who you're talking to and what you don't know. A friend asking where the party is gets a different answer than a stranger asking you for directions, or a teacher asking a grammar question.

There's also a trap lurking: French has two verbs for "to know", savoir and connaître. Pick the wrong one and your sentence sounds odd. This post gives you the standard phrase, casual and formal alternatives, and a simple rule for the two verbs.

The Standard Phrase: Je Ne Sais Pas

The all-purpose way to say I don't know in French is je ne sais pas. It works in every situation, from a market stall to a job interview.

Key Phrases

• Je ne sais pas (zhuh nuh say pah) — I don't know
• Je sais (zhuh say) — I know
• Tu sais ? (tew say) — Do you know?
• Vous savez ? (voo sah-vay) — Do you know? (polite or plural)
• Je ne sais pas du tout (zhuh nuh say pah dew too) — I have no idea at all

[AUDIO: je ne sais pas]

Grammar Note

Savoir (to know a fact or know how to do something) is irregular. In the present tense it goes:

• je sais
• tu sais
• il/elle sait
• nous savons
• vous savez
• ils/elles savent

To make it negative, wrap ne and pas around the verb. A common mistake is forgetting ne in writing, so "Je sais pas" is fine in a text to a friend but not in an email to your landlord.

In everyday speech, French people often drop the ne and even squash the words together so that je ne sais pas sounds like "shay pa". You'll see it written as chais pas in text messages and comics. Don't copy it in class or at work, but do learn to recognize it, or you'll miss it constantly.

Casual Ways to Say You Don't Know

With friends, you have plenty of relaxed options that sound far more natural than a textbook phrase.

Key Phrases

• J'en sais rien (zhahn say ree-ahn) — I have no clue
• Aucune idée (oh-kewn ee-day) — No idea
• Pas la moindre idée (pah lah mwahn-druh ee-day) — Not the faintest idea
• Bonne question ! (bun kes-tee-ohn) — Good question!
• Je n'en ai aucune idée (zhuh nahn ay oh-kewn ee-day) — I have no idea about that

Aucune idée is probably the most useful of these. It needs no verb, so it's quick to say when you're caught off guard. Add a shrug and a puff of air, and you'll sound very French.

J'en sais rien uses rien (nothing) in a slightly different way: the en means "about it", so literally you know nothing about it. It can sound a little curt, so save it for people you know well.

Polite and Formal Ways to Say It

When a stranger, customer, or boss asks you something, softer phrases work better than a flat je ne sais pas.

Key Phrases

• Je suis désolé(e), je ne sais pas (zhuh swee day-zoh-lay) — I'm sorry, I don't know
• Je l'ignore (zhuh lee-nyor) — I'm not aware of it (formal)
• Je ne suis pas au courant (zhuh nuh swee pah zoh koo-rahn) — I'm not up to speed on that
• Je ne suis pas sûr(e) (zhuh nuh swee pah sewr) — I'm not sure
• Je vais me renseigner (zhuh vay muh rahn-seh-nyay) — I'll find out

Notice that je l'ignore looks like "I ignore it", but it actually means "I don't know about it". It's a classic false friend, and one you'll mostly read in formal writing rather than hear in the street.

The last phrase is a gem in professional settings: instead of just admitting you don't know, you promise to find the answer.

Savoir or Connaître? A Simple Rule

This is where many learners slip. Both verbs translate as "to know", but they aren't interchangeable.

• Use savoir for facts, information, and learned skills: Je ne sais pas l'heure (I don't know the time), Je ne sais pas nager (I can't swim).
• Use connaître for people, places, and things you're familiar with: Je ne connais pas ce restaurant (I don't know this restaurant), Je ne connais pas Marie (I don't know Marie).

A handy test: if you could replace "know" with "be familiar with", choose connaître. If you could replace it with "know that" or "know how", choose savoir.

In French shops and train stations, you'll often hear Je ne connais pas bien le quartier (I don't know the neighborhood well) from locals who've just moved in. Admitting you don't know a place is completely normal and usually invites a friendly "moi non plus !" (me neither!).

Putting It Into Practice

Imagine you're lost in Lyon and a stranger asks Excusez-moi, vous savez où est la gare ? (Excuse me, do you know where the station is?) Here's how the exchange could go:

• Step 1: Answer politely with Désolé, je ne sais pas. (Sorry, I don't know.)
• Step 2: Add Je ne suis pas d'ici. (I'm not from here.)
• Step 3: Offer help with Peut-être qu'on peut demander à quelqu'un ? (Maybe we can ask someone?)

Now try the casual version with a friend asking Il arrive à quelle heure, Paul ? (What time is Paul arriving?). You can reply Aucune idée, je lui demande. (No idea, I'll ask him.)

Practice Exercises

• Translate into French: I don't know.
• Fill in the blank with savoir or connaître: Je ne ___ pas ton frère.
• Fill in the blank: Nous ne ___ pas la réponse. (savoir, present tense)
• Multiple choice: Which phrase means "No idea"? (a) Aucune idée (b) Je l'ignore (c) Bonne question
• Translate into French, politely: I'm sorry, I don't know. I'll find out.
• True or false: Chais pas is a good choice for a formal email.

Answer Key

• Je ne sais pas.
• connais (Je ne connais pas ton frère, because it's a person)
• savons (Nous ne savons pas la réponse)
• (a) Aucune idée.
• Je suis désolé(e), je ne sais pas. Je vais me renseigner.
• False. Chais pas is very informal spoken French.

Conclusion and Next Steps

Key takeaways:

• Say je ne sais pas in any situation, and drop to aucune idée or j'en sais rien with friends.
• Use savoir for facts and skills, connaître for people and places.
• Soften your answer with désolé(e) or je vais me renseigner when speaking to strangers or at work.

Ready for more? Try our lesson on how to say I don't understand in French, and tell us in the comments which French phrase you'd like to learn next.