German modal verbs — can, must, want, should, may, like

Modal verbs sit in front of another verb and change what the sentence is doing: an ability, an obligation, a wish, a permission. They are among the most common verbs in German and they behave unlike anything else.

Two things happen when you use one:

1. The modal takes the normal verb position, second in the sentence.
2. The real verb goes to the very end, as an infinitive.

Ich kann heute nicht arbeiten. — I cannot work today.

English puts "work" in the middle. German holds it back to the end, and building that habit is most of the work here.

The six

The irregular part

Every modal changes its vowel in the singular and then behaves normally in the plural. This is the bit that has to be learned.

ich and er/sie/es are identical — no -t on the third person. That holds for all six, and it is the most common mistake beginners make with them.

sollen is the odd one out: no vowel change at all. ich soll, du sollst, er soll.

möchten, the one that is not quite a verb

möchten means "would like" and is how you ask for things politely. Technically it is a form of mögen; everybody treats it as its own verb because that is how it is used.

Ich möchte einen Kaffee, bitte. — I would like a coffee, please.

Use möchten to order and request. Use wollen only when you mean want bluntly — ich will lands harder than "I want" does in English.

nicht müssen is the trap

nicht müssen does not mean must not. It means do not have to.

Du musst nicht kommen. — You do not have to come.

To say must not, use nicht dürfen:

Du darfst nicht kommen. — You are not allowed to come.

This one reverses the meaning of a sentence, and it is worth checking twice.

In the past

All six form their past with the simple past rather than the perfect, even in speech — the one place German prefers Präteritum in conversation. The vowel loses its umlaut and adds -te.

Ich konnte gestern nicht kommen. — I could not come yesterday.

More on which past tense to use in Perfekt or Präteritum.

What to actually memorise

The singular vowel changes, and the nicht müssen against nicht dürfen distinction. The word order looks after itself once you have said a few sentences aloud — the verb arriving at the end starts to feel natural faster than you expect.