8 different ways to say I don’t know in French

So, we learn French and spend ages with our noses in the textbook or in lessons. It's what we do.

Then we dare to step out of our comfort zone and speak to someone. And sometimes, it just all goes wrong! 

Today’s example is when you learn “Je ne sais pas” but totally zone out when someone slips in the more popular “chais pas, moi” casually shrugging their shoulders as you stand there trying to work out what just hit you!

Forgive them - it’s ok to have that problem. 

 Therefore, today you will see:

• What ‘chais pas’ means
• More ways of saying you really don’t know
• Shorter versions of “I don’t know” using à & en

8 different ways to say I don’t know in French.

Before diving into the subject, let’s introduce our 8 expressions to express uncertainty or lack of information:

• Je ne sais pas

• Chais pas

• Je n’ai aucune idée

• Aucune idée

• Pas la moindre idée

• Je ne sais rien de cela
• Je n’en sais rien
• Je ne suis pas certain(e) de pouvoir y répondre

As you can see, some sentences are similar. Oui! You are right. However, the register and the grammatical structure differ…

Let’s analyse them in the following sections.

The regular, and more popular,  expression for “I don’t know” in French. 

First things first. The direct French translation of “I don’t know” is: Je ne sais pas.

Why? Because the verb “savoir” is to know. This is how you conjugate this irregular verb:

• Je sais >>> I know 
• Tu sais >>> you know 
• Il / elle sait >>> s/he know 
• Nous savons >>> we know 
• Vous savez >>> you know 
• Ils / elles savent >>> they know 

And the opposite of "to know" is the negative form. As a result, you’ll have the following:

• Je ne sais pas >>> I don’t know 
• Tu ne sais pas >>> you don’t know 
• Il / elle ne sait pas >>> s/he doesn’t know 
• Nous ne savons pas >>> we don’t know 
• Vous ne savez pas >>> you don’t know 
• Ils / elles ne savent pas >>> they don’t know 

If you don’t know how to use the negative form in French or forgot it, here’s a video for you.   

Now, the sentence “je ne sais pas” has some variations. When you talk fast, you can omit the “ne” and have “je sais pas”. And even faster, you can say or hear “chais pas”.

You don’t really see this in books but I promise you that most French people prefer the last version while talking to their friends!

So, here are 2 examples:

• Je ne sais pas >>> I don’t know.
• Chais pas (moi) >>> I dunno.

Do you better memorise things with songs? If oui, I have several songs for you to practice this sentence. First, the song of “Je ne sais pas” by Joyce Johnathan then the memorable Céline Dion’s song “Je sais pas”  and this new song by Camille with the formal and informal versions!

In French, there are 2 verbs with the same English translation of the verb “to know”: 

• savoir
• connaître

The first one refers more to your abilities and the other describes your knowledge.

4 ways to say “I have no idea” in French.

Time to discover how to say you don’t have any idea. Again, you will see the same sentence with few words.

Let’s have a look at the examples:

• Je n’ai aucune idée  >>> I have no idea.
• J’ai aucune idée  >>> I‘ve no idea.
• Aucune idée  >>> No idea.
• Pas la moindre idée  >>> Not the foggiest.

The first sentence is complete. The second one is a spoken one. The third is rather short. And the last one stresses the absence of knowledge. Bear in mind that only the first sentence is correct. The others are when you speak. 

2 alternatives for saying “I don’t know about that” in French.

This time, we will explain how to use pronouns in order to avoid repetition.

First, you will see the extended version like in this example:

• Je ne sais rien de cela  >>> I don’t know anything about that.

And with the adequate pronoun, you have this:

• Je n’en sais rien  >>> I don’t know anything about that.

With indirect verbs (verbs with the preposition de ), the pronoun en is required. Here are some verbs to consider: avoir besoin de (need), rêver de (dream), avoir envie de (feel like), s’occuper de (take care of)...

If you’re not sure about the prepositions with a verb, you may be interested in these posts:

Penser A or DE ?

12 common verbs with the preposition À

How to say “I’m not sure”  in French.

Let’s do the same but with another pronoun!

Again, you will see the extended version:

• Je ne suis pas certain(e) de pouvoir répondre à cette question. >>> I’m not sure I can answer that question.

And with the adequate pronoun, you have this:

• Je suis pas certain(e) de pouvoir y répondre. >>> I’m not sure I can answer that.

Because the indirect verb goes with the preposition à ), the pronoun y is mandatory. Here are some verbs to consider: penser à (think about), s’intéresser à (be interested in), réfléchir à (think about)...

To summarise, whenever you don’t know about a thing, you have 8 options.

The usual answer with its informal version:

• Je ne sais pas

• Chais pas

When you don’t have any ideas with reducing your sentence:

• Je n’ai aucune idée / J’ai aucune idée

• Aucune idée
• Pas la moindre idée

With the pronoun “en”:

• Je ne sais rien de cela
• Je n’en sais rien

And finally, with the pronoun “y”:

• Je ne suis pas certain(e) de pouvoir y répondre

I seriously hope that you do know about these phrases and that you have a clear idea about how to answer when in spontaneous conversation.

It’s in your interest to know the colloquial versions in order to understand real French conversations. After all, you don't want that awful brain freeze just because you're unfamiliar!

As always - any questions, send them over. I LOVE to help.