Modal Verbs

There are six verbs which are very commonly used in German. They are irregular and are mostly used with another verb, which is always in the infinitive form and at the end or the clause or sentence. Note there is no need to use zu with the infinitive.

E.g

Ich muss meine Hausaufgaben machen

Er darf in die Disko gehen

Wir wollen nach Bath fahren

The six verbs are:

dürfen - to be allowed to

können - to be able to

mögen - to like to

müssen -to have to

sollen - to be supposed to

wollen - to wish / want to

The present indicative of each verb is slightly irregular, as follows:

Modal verbs can be used in the past tense in either the perfect or imperfect tense.

The Imperfect indicative endings are the weak verb forms -te, etc., i.e.

ich durfte, ich konnte, ich mochte, ich musste, ich sollte, ich wollte.

The same rule applies where the infinitive goes to the end.

So, ich musste meine Hausaufgaben machen (I had to do my homework)

Wir wollten nach Bath fahren (we wanted to go to Bath)

In the perfect tense, all six modal verbs use haben as the auxiliary, but the past participle is hardly ever used (only when there is not another dependent infinitive, e.g. ich habe es gewollt - I wanted it - no other verb in the sentence). The past participle is replaced by the infinitive in the perfect tenses.

E.g. Er hat nicht gehen können. He has not been able to go

Ich habe ins Kino gehen wollen. I wanted to go to the cinema

CAREFUL!

When a verb kicker is involved the verb haben resets in front of the two other verbs, instead of being kicked to the end!

Obwohl ich meine Hausaufgaben habe machen sollen, bin ich ausgegange.

Wir waren froh, weil wir ins Kino haben gehen können

The conditional perfect is also worth taking note of!

Ich hätte es tun dürfen - I should have been allowed to do it

Ich hätte es tun mögen - I should have liked to do it

Ich hätte es tun müssen - I should have had to do it

Ich hätte es tun  wollen - I should have wanted to do it

Ich hätte es tun können - I should have wanted to do it

Ich hätte es tun sollen - I ought to have done it (The most useful for coursework!!)

So,

ich hätte meine Hausaufgaben machen sollen, aber.... ( I should have done my homework, but...)

ich hätte den Rasen mähen sollen, aber statt dessen bin ich ausgegangen ( I should have mowed the lawn, but instead I went out)