German Modal Verb Müssen Explained

Müssen is German's verb for necessity — and negating it doesn't work the way most English speakers expect. In this lesson, we cover the conjugation of müssen, the situations where it's used, and the common alternative nicht brauchen zu.

Conjugation of Müssen

ich muss, du musst, er/sie/es muss, wir müssen, ihr müsst, sie/Sie müssen.

When to Use Müssen

Müssen expresses necessity or obligation, usually paired with a second verb in the infinitive at the end of the sentence: Ich muss arbeiten. (I have to work.)

The Trap: Nicht Müssen Doesn't Mean “Must Not”

Negating müssen means “don't have to,” not “must not”: Du musst das nicht machen. (You don't have to do that.) A common alternative with the same meaning is nicht brauchen zu: Du brauchst das nicht zu machen. To say “must not,” German uses nicht dürfen instead.

Frequently Asked Questions

How do you conjugate “müssen” in German?

Ich muss, du musst, er/sie/es muss, wir müssen, ihr müsst, sie/Sie müssen.

Does “nicht müssen” mean “must not” in German?

No — it means “don't have to.” To say “must not,” German uses nicht dürfen instead.

What is “nicht brauchen zu”?

A common alternative to nicht müssen with the same meaning: Du brauchst das nicht zu machen equals Du musst das nicht machen.

How do you say “I have to work” in German?

Ich muss arbeiten.

Is “müssen” one of the German modal verbs?

Yes — müssen is one of the six core modal verbs, along with können, mögen, wollen, dürfen, and sollen.

Ready to master every German modal verb? Start with our A1 German course.