B1 – Intermediate

müssen

must / to have to

1. Meet the verb

müssen means must / to have to.

Use müssen for strong obligation or necessity: taking medicine, going to the doctor, resting.

2. Focus for B1 – Perfect tense with double infinitive

We use the perfect tense to say what someone has had to do, has been able to do, etc. The modal stays as an infinitive at the very end.

Pattern: Subject + haben (conjugated) + ... + main verb infinitive + modal infinitive.

In the perfect tense the modal verb stays as an infinitive at the end. The auxiliary haben is conjugated:

PersonContexthaben (auxiliary)
ichIhabe
duyou (one person, informal)hast
er/sie/eshe / she / ithat
wirwehaben
ihryou (several people, informal)habt
sie/Siethey / you (formal, one or more people)haben

Structure: subject + haben + ... + main verb infinitive + müssen

Pronoun guide

German has three ways to say you:

The word sie (lowercase) can also mean she or they. Context and the verb form tell them apart:

Clinical register: In medical practice, use Sie with patients. Du/ihr are for colleagues, friends, or family.

Medical examples with the three you forms:

Vocabulary you will need
3. Medical examples
How the exercises work
4. Remember this
In the perfect tense, müssen stays as an infinitive at the very end, after the main verb: the double-infinitive order is ... + main verb + müssen.
Do not move the modal verb before the main verb: Ich habe zum Arzt gehen müssen. (Not: Ich habe müssen zum Arzt gehen.)
5. Quick self-check

Translate to German: You (formal) have had to go to the doctor

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Sie haben zum Arzt gehen müssen.

Translate to German: You (informal, one person) have not had to take the tablet

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Du hast die Tablette nicht nehmen müssen.

Ask the question in German: Have you (informal, one person) had to drink a lot of water?

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Hast du viel Wasser trinken müssen?

Put the words in the correct order: bleiben / hat / Patient / Der / im / Bett / müssen

Show answer

Der Patient hat im Bett bleiben müssen

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Practice this verb with exercises, or take a mixed test with all verbs.

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