Modal Auxiliary Verbs

You may also know these verbs as “helping verbs” because that’s exactly what they do, help to convey the idea expressed by another verb.

There are six modal auxiliaries in German, here presented with their definitions and a rough English equivalent:

dürfenpermissionto be allowed to, may
wollenintention, desireto want to
sollenduty, expectancyto have to, shall
müssennecessity, compulsionto have to, must
mögenpossibilityto possibly do, might
könnenabilityto be able to, can

These auxiliaries are almost always followed by infinitives. The infinitives never take zu.

Wir müssen es lernen.
We have to learn it.

Ich kann dieses Buch nicht verstehen.
I can’t understand this book.