The modal verb: müssen
The modal verb müssen is used to express obligation or necessity—things you "must" or "have to" do.
Like other modal verbs, the singular forms have a stem vowel change (from ü to u), and the ich and er/sie/es forms are identical with no ending.
| Pronoun | Conjugation |
|---|
| ich | muss |
| du | musst |
| er/sie/es | muss |
| wir | müssen |
| ihr | müsst |
| sie/Sie | müssen |
Sentence structure
Remember the "sentence bracket" rule: the conjugated modal verb takes the second position, and the main action verb is pushed to the very end of the sentence in its infinitive (dictionary) form.
For yes/no questions, the conjugated modal verb moves to the very first position, but the main action verb still stays at the end.
The modal verb: dürfen
The modal verb dürfen expresses permission—things you "may" or "are allowed to" do.
Its singular forms also have a stem vowel change, this time from ü to a.
| Pronoun | Conjugation |
|---|
| ich | darf |
| du | darfst |
| er/sie/es | darf |
| wir | dürfen |
| ihr | dürft |
| sie/Sie | dürfen |
Prohibition (must not)
In English, "must not" sounds like the opposite of "must." However, in German, to say that something is prohibited (that you "must not" do it), you use dürfen with a negative word like nicht or kein. It literally translates to "not allowed to."
When combining two clauses, you can contrast what is prohibited with what is required:
