German modal verbs: all 6 conjugated

Modal verbs express possibility, necessity, permission, or desire — they modify the main verb rather than describe an action directly. German has 6 modals: können (can/to be able), müssen (must/to have to), dürfen (may/to be allowed), sollen (should/to be supposed to), wollen (to want), and mögen/möchten (to like/would like). They always pair with an infinitive at the end of the clause.

Yes, but the Perfekt of modal verbs is unusual. When a modal is used with an infinitive, the Perfekt uses the infinitive form of the modal (called the "double infinitive"): "Ich habe gehen müssen" (I had to go). When a modal is used without an infinitive, the normal past participle is used: "Das habe ich gewollt" (That is what I wanted). In practice, the Präteritum form is more common than Perfekt for modals in German.

Müssen expresses internal necessity or logical conclusion — you feel compelled by circumstances: "Ich muss arbeiten" (I have to work — because I need money). Sollen expresses external expectation — someone else has told you to do something: "Ich soll arbeiten" (I'm supposed to work — my boss said so). The key distinction: müssen comes from within, sollen comes from without.

Modal verbs follow the Satzklammer (sentence bracket) rule: the conjugated modal occupies position 2 (after the subject), and the main verb infinitive goes to the end of the clause. "Ich kann heute nicht kommen" — kann is in position 2, kommen is at the end. In subordinate clauses, both the modal and the infinitive go to the end, with the modal last: "..., weil ich nicht kommen kann."