müssen

Modal Verb Müssen

Level 1

The modal verb müssen is used for things you have to do. In a sentence, it takes the second position, while the action verb moves to the very end in its infinitive form.

How It Works

1. Meaning and Usage
The verb müssen expresses that something is necessary. This can be due to rules, laws, or personal needs.

  • Ich muss schlafen. (I have to sleep - personal need)
  • Wir müssen arbeiten. (We have to work - external obligation)

Nuance: In casual speech, you can often omit the main verb if the direction is clear: Ich muss nach Hause (gehen). It can also express a logical conclusion: Er muss krank sein. (He must be sick.)

2. Conjugation (Present Tense)
Modal verbs are slightly irregular. Notice that the stem vowel changes from ü to u in the singular, and the ich and er/sie/es forms have no ending:

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

3. Sentence Structure
When using müssen with another verb, follow the modal verb construction:

  • Statements: Place the conjugated form of müssen in the second position and the infinitive at the end. Ich muss heute meine Hausaufgaben machen.
  • Questions: In Yes/No Questions, the modal verb moves to the first position. Musst du heute arbeiten?

4. The Negation Trap
In English, 'must not' means it is forbidden. In German, nicht müssen means you don't have to (it's optional). If you want to say something is forbidden, use dürfen nicht.

Examples (5)

  1. Ich muss jetzt nach Hause gehen.

    I have to go home now.

    Word by Word: I must now to house go.

    The conjugated 'muss' is in position 2, and the infinitive 'gehen' is at the end.

  2. Du musst leise sein.

    You must be quiet.

    Word by Word: You must quiet be.

    Used here to express a situational necessity.

  3. Wir müssen heute nicht arbeiten.

    We don't have to work today.

    Word by Word: We must today not work.

    Negating 'müssen' means there is no obligation; it is optional.

  4. Er muss eine Brille tragen.

    He has to wear glasses.

    Word by Word: He must a glasses wear.

    Shows a physical necessity or requirement.

  5. Müsst ihr am Samstag lernen?

    Do you (plural) have to study on Saturday?

    Word by Word: Must you on Saturday study?

    In a question, the modal verb moves to the first position.

Common Mistakes

  • Using 'zu' with the infinitive.

    Ich muss zu essen.
    Ich muss essen.

    Modal verbs in German never take 'zu' before the infinitive verb at the end of the sentence.

  • Using 'muss nicht' for prohibition (forbidden actions).

    Du musst hier nicht rauchen.
    Du darfst hier nicht rauchen.

    'Du musst nicht' means 'You don't have to (but you can)'. To say 'You must not', use 'darfst nicht'.

  • Incorrect third-person singular conjugation.

    Er musst gehen.
    Er muss gehen.

    The 'ich' and 'er/sie/es' forms of modal verbs never end in -t. They are always identical.

How It Connects

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müssenLevel 1Modal Verb Müssen

Learn This First

To learn 'müssen', you need to understand basic verb conjugation and how German sentence structure handles two verbs (the modal verb and the infinitive).

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