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See also: mussen and muessen



From Old High German muozan, from Proto-Germanic *mōtaną. The closeness to the original diphthong can for example still be seen in the Bavarian first and third person singular, where one says I muas (I must) or Ea/Si/Es muas (He/she/it must).


  • IPA(key): /ˈmʏsən/, [ˈmʏsən], [ˈmʏsn̩]
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müssen (irregular, third-person singular simple present muss, past tense musste, past participle gemusst, auxiliary haben)

  1. (auxiliary, with an infinitive → “müssen” replaces the past participle) to have to (do something); must; to be obliged (to do something); to need (to do something).
    Wir müssen es machen. — “We must do it.”
    Wir müssen es nicht machen. — “We need not do it.” or “We do not need to do it.”
    Ich musste es machen. — “I had to do it.”
  2. (intransitive, with past participle “gemusst) to have to do something implied; must; to be obliged.
    Ja, ich muss. — “Yes, I must.”
    Ja, ich habe gemusst. — “Yes, I had to.”
  3. (colloquial, euphemistic) to need to go to the bathroom.

Usage notes[edit]

  • Müssen can express the necessity of doing something, but also the moral duty. Sollen expresses moral duty or the suggestion that something ought to be done. Both verbs can express a duty imposed by someone else. In this case müssen is stronger than sollen, implying that the imposing person has some kind of power to make the other really do it.
  • As shown in the first line, the infinitive is used instead of the past participle in the compound tenses if the verb has a complement verb. The phenomenon is called double infinitive.
Das hätten wir machen müssen.
We should have done that.
  • In southern German and Austrian speech, the infinitive is often used instead of the past participle in any construction. Thus: ich habe nicht müssen for standard ich habe nicht gemusst.
  • As shown in the example above, nicht müssen translates into English as “need not” rather than “must not”. For the English “must not”, use nicht dürfen.
  • Before 1996, several of the conjugated forms of müssen were spelled with an ß (that is, muß, mußte, müßte, etc.). Since the spelling reform of 1996, however, the acceptable spelling is with ss.


Further reading[edit]