what is it?
Modal verbs are a small, closed set of auxiliary verbs — können (can / be able to), wollen (want to), müssen (must / have to), dürfen (may / be allowed to), sollen (shall / be supposed to), and mögen (like), together with its polite form möchte- (would like to) — that combine with a bare infinitive to express ability, necessity, permission, obligation, or desire. In a main clause, the modal verb takes the second position and the infinitive moves to the very end of the clause, forming what is called the verb bracket (Satzklammer).
when to use it
Ability: use können to say what someone is able to do. «Ich kann schwimmen.» (I can swim.)
Desire / intention: use wollen for a strong personal want, or möchte- for a polite request or wish.
Necessity / obligation: use müssen when something is required or unavoidable.
Permission: use dürfen to express what is allowed or not allowed.
Expectation / suggestion: use sollen when someone is supposed to do something, or in questions like «Sollen wir …?» to make a suggestion (equivalent to English «Shall we …?»).
Liking: use mögen to say you like something (often without an infinitive at A1), or möchte- with an infinitive to say you would like to do something.
formation
Modal verbs have two irregular features in the present tense. First, the 1st and 3rd person singular share the same form and carry no ending. Second, most modals lose the umlaut in the singular (können → kann, müssen → muss). The plural forms are regular. The möchte- forms are already past-subjunctive in origin and follow their own pattern — treat them as a fixed set.
| pronoun | können | wollen | müssen | dürfen | sollen | möchte- |
|---|---|---|---|---|---|---|
| ich | kann | will | muss | darf | soll | möchte |
| du | kannst | willst | musst | darfst | sollst | möchtest |
| er/sie/es | kann | will | muss | darf | soll | möchte |
| wir | können | wollen | müssen | dürfen | sollen | möchten |
| ihr | könnt | wollt | müsst | dürft | sollt | möchtet |
| sie/Sie | können | wollen | müssen | dürfen | sollen | möchten |
Word order in a main clause follows the verb bracket: the modal verb occupies position 2, and the bare infinitive goes to the end of the clause. Everything else — objects, adverbs, negation — sits between the two verbs.
Pattern: [Subject] + [modal] + … + [infinitive] — e.g. «Wir müssen morgen früh aufstehen.»
examples in context
common pitfalls
Adding -t to the 3rd person singular. Modal verbs take no ending in the 3rd person singular. Write er kann, sie muss — not *er kannt or *sie musst.
Placing the infinitive directly after the modal. The infinitive must go to the end of the clause. «Ich will nach Hause gehen.» — not *Ich will gehen nach Hause.
Keeping the umlaut in the singular. The singular stem of most modals drops the umlaut: er kann (not *er könnt), sie muss (not *sie müsst). The umlaut forms belong to the plural (wir können, wir müssen).
Using zu before the infinitive. After a modal verb, the infinitive is always bare — no zu. «Ich muss arbeiten.» — not *Ich muss zu arbeiten.
Adding können to perception verbs. English uses «can see / can hear», but German perception verbs already imply ability on their own. The default is simply «Ich sehe das Meer.» (I can see the sea.) — not *Ich kann das Meer sehen as a direct translation of the English pattern.