In German
Ich weiß nicht
Meaning: I don't know
Formal or informal? “Ich weiß nicht” is the everyday phrase. A polite, more careful version is “Das weiß ich leider nicht” (I'm afraid I don't know that).
Example sentences
Ich weiß nicht.
I don't know.
Ich weiß es nicht genau.
I don't know it exactly.
Weißt du das? Nein, ich weiß nicht.
Do you know that? No, I don't.
Grammar note
“Wissen” is irregular in the singular: ich weiß, du weißt, er weiß. “Nicht” goes at the end of the clause when the sentence has no other object.
Common mistake
Don't say “Ich kenne nicht” for “I don't know”. “Kennen” means to know a person or place, while “wissen” means to know a fact.
Quick check
Which German phrase means “I don't know”?
More words on this topic
Keep learning German
Practise it in a lesson →Frequently asked questions
What is the difference between “wissen” and “kennen”?
“Wissen” is to know a fact, while “kennen” is to know a person or place.
How do you say “I'm afraid I don't know” politely?
“Das weiß ich leider nicht”.