Modal verbs are the small set of helper verbs that let you say what you can, must, may, should, want, or like to do. German has exactly six, and the wonderful thing is that they all share one grammar pattern and one irregular conjugation shape. Learn the system once and all six fall into place.
The six modal verbs
| Modal | Core meaning |
|---|---|
| können | can, to be able to |
| müssen | must, to have to |
| dürfen | may, to be allowed to |
| sollen | should, to be supposed to |
| wollen | to want to |
| mögen | to like |
(A seventh form, möchte "would like," is the Konjunktiv II of mögen and is taught alongside it.)
The shared word order: modal in position 2, infinitive at the end
This is the single most important rule and it never varies. The modal is the conjugated verb and sits in position 2. The main verb goes to the very end of the clause as a bare infinitive — that is, an infinitive with no zu in front of it.
Ich kann gut schwimmen.
I can swim well.
Du musst jetzt gehen.
You have to go now. (informal)
Wir wollen am Wochenende ins Kino gehen.
We want to go to the movies at the weekend. (informal)
The conjugated modal and the final infinitive form a verb bracket (Satzklammer). Everything else — objects, adverbs, time and place — sits neatly between them:
[ Ich ] kann [ heute Abend leider nicht ] kommen.
Ich kann heute Abend leider nicht kommen.
Unfortunately I can't come this evening. (informal, apologetic)
The irregular present tense: no -t in the er-form, and a vowel change in the singular
Modals do not conjugate like normal verbs. Two oddities define them.
1. The singular changes its vowel. Five of the six swap the infinitive vowel for a different vowel in the ich/du/er forms (only sollen keeps its vowel). This is the same vowel that appears in their past tense, a clue to their ancient origins.
2. The ich and er forms are identical, with no ending. Where a normal verb adds -e to ich and -t to er (ich komme, er kommt), modals add nothing: ich kann, er kann. The ich form and the er form look exactly alike.
| können | müssen | dürfen | sollen | wollen | mögen | |
|---|---|---|---|---|---|---|
| ich | kann | muss | darf | soll | will | mag |
| du | kannst | musst | darfst | sollst | willst | magst |
| er/sie/es | kann | muss | darf | soll | will | mag |
| wir | können | müssen | dürfen | sollen | wollen | mögen |
| ihr | könnt | müsst | dürft | sollt | wollt | mögt |
| sie/Sie | können | müssen | dürfen | sollen | wollen | mögen |
Read down any column and you see the pattern: a single singular vowel (kann, muss, darf, will, mag) shared by ich and er, then the plural snaps back to the infinitive vowel with umlaut where the infinitive has one (können, müssen, dürfen).
Er muss heute länger arbeiten.
He has to work longer today. (note: er muss, no -t)
Magst du Kaffee?
Do you like coffee? (informal)
The vowel returns to the umlaut in the plural
Notice that the singular vowels lose their umlaut (können → kann, müssen → muss, dürfen → darf), and the plural restores the infinitive's umlaut (können, müssen, dürfen). Watch this carefully, because it also distinguishes the indicative from the Konjunktiv II later on (konnte "was able" vs könnte "could"). See Konjunktiv II of modals.
How this differs from English
English modals (can, must, may, should, will) are famous for being defective: they take no "to," no "-s" in the third person (he can, not he cans), and they cannot stack. German modals share the no-"to" rule and the bare third person, but they are fully conjugating verbs with all six forms, a past tense, and a participle. So while English "can" stops at "could," German können keeps going: konnte, gekonnt, könnte. German modals can even appear with no main verb at all (Ich kann Deutsch "I can speak German," Ich muss nach Hause "I have to go home"), which English allows only marginally.
Ich muss nach Hause.
I have to go home. (informal — no main verb; gehen is understood)
Das darf doch nicht wahr sein!
That can't be true! / You've got to be kidding! (informal exclamation)
Common Mistakes
❌ Ich kann zu schwimmen.
Wrong: no zu before the infinitive after a modal.
✅ Ich kann schwimmen.
I can swim.
❌ Er kannt gut kochen.
Wrong: modals take no -t in the er-form. It's er kann, like ich kann.
✅ Er kann gut kochen.
He can cook well.
❌ Ich will gehen ins Kino.
Wrong word order: the bare infinitive must go to the very end, after the place phrase.
✅ Ich will ins Kino gehen.
I want to go to the movies. (informal)
❌ Wir musst arbeiten.
Wrong: wir takes the plural form müssen, not the du-form musst.
✅ Wir müssen arbeiten.
We have to work.
❌ Ich kanne Deutsch sprechen.
Wrong: there is no -e ending on the ich-form of a modal. It's ich kann.
✅ Ich kann Deutsch sprechen.
I can speak German.
Key Takeaways
- The six modals are können, müssen, dürfen, sollen, wollen, mögen.
- The modal is conjugated in position 2; the main verb goes to the end as a bare infinitive (no zu).
- In the present singular the vowel changes and there is no ending on ich or er — the two forms are identical.
- The plural restores the infinitive's vowel (with umlaut: können, müssen, dürfen).
- Each modal has its own page: start with können, müssen, and dürfen; for the past see the modal Perfekt and double infinitive.
Now practice German
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Start learning German→Related Topics
- können: Ability, Possibility, PermissionA2 — The full conjugation and meanings of können — ability, possibility and informal permission — plus the könnte / konnte trap that turns on a single umlaut.
- müssen: Necessity and ObligationA2 — The full conjugation and meaning of müssen — plus the meaning-reversing negation trap: nicht müssen means 'needn't', and English 'must not' is darf nicht.
- dürfen: Permission and ProhibitionA2 — How to use dürfen for permission, prohibition (nicht dürfen = 'must not'), polite offers, and the dürfte probability marker.
- The Bare Infinitive (without zu)B1 — The small set of verbs — modals, perception verbs, lassen, and motion verbs — that take a plain infinitive with no zu, and the double-infinitive Perfekt they trigger.
- Modals in the Perfekt and Subordinate ClausesB2 — Why modals prefer the Präteritum in speech, how the double infinitive (Ersatzinfinitiv) works, when the participle gekonnt/gemusst appears, and how subordinate clauses front the auxiliary.
- Konjunktiv II of Modal VerbsB1 — könnte, müsste, dürfte, sollte, möchte — the high-frequency modal subjunctives behind polite and tentative German, and the umlaut that separates them from the plain past.