German Modal Verbs: Conjugation of 'Duerfen,' 'Koennen,' and 'Moegen'

Conjugating the German modal verbs is an important part of learning the language. The tables below show how to conjugate three modal verbs, dürfen, können, and mögen, including examples of how they are used in sample modal sentences and expressions. There are actually six modal verbs in German:

• Dürfen> may, be permitted   
• Können > can, be able
• Mögen > like   
• Müssen > must, have to
• Sollen > should, ought to   
• Wollen > want to

Modals derive their name from the fact that they always modify another verb. Additionally, they are always used in tandem with the infinitive form of another verb, as in, Ich muss morgen nach Frankfurt fahren (ich muss + fahren), which translates as "I have to go to Frankfurt tomorrow."

The modal verbs in the table are presented in all of their tenses. For all modals with umlauts, the simple past (preteriteImperfekt) has no umlaut, but the subjunctive form always has this diacritical mark.

* In the present perfect or past perfect tense with another verb, the double infinitive construction is used, as in the following examples:

ihr habt sprechen dürfen = you (pl.) were allowed to speak
ich hatte sprechen dürfen = I had been allowed to speak

Present: Darf ich rauchen? May I smoke?
Past/Preterite: Er durfte das nicht. He wasn't permitted to do that.
Pres. Perfect/Perfekt: Er hat dort nicht parken dürfen. He was not permitted to park there.
Past Perfect/Plusquamperfekt: Wir hatten das damals machen dürfen. We had been allowed to do that back then.
Future/Futur: Wir werden das machen dürfen. We will be allowed to do that.
Subjunctive/Konjunktiv: Wenn ich dürfte... If I were permitted...

Was darf es sein? May I help you? (store clerk)
Wenn ich bitten darf. If you please.

* In the present perfect or past perfect tense with another verb, the double infinitive construction is used, as in the following examples:

Wir haben schwimmen können. = We were able to swim.
Ich hatte schwimmen können. = I had been able to swim.

Present: Er kann gut fahren. He can drive well.
Past/Preterite: Er konnte sie nicht leiden. He couldn't stand her.
Pres. Perfect/Perfekt: Er hat sie nicht leiden können. He couldn't stand her.
Past Perfect/Plusquamperfekt: Er hatte sie nicht leiden können. He had not been able to stand her.
Future/Futur: Er wird sie nicht leiden können. He won't be able to stand her.
Subjunctive/Konjunktiv: Wenn ich ihn nur leiden könnte... If I could only stand him...

Sie könnten sich irren. You could be mistaken.
Das kann man wohl sagen. You can say that again.
Er kann Deutsch. He knows German. ("can German")
Er kann Sie jetzt sprechen. He can see you now. (doctor, dentist) 

* In the present perfect or past perfect tense with another verb, the double infinitive construction is used, as in the following examples:

Wir haben schwimmen mögen. = We liked to swim
Ich hatte schwimmen mögen. = I had liked to swim

mögen is often used in its subjunctive (möchte) "would like" form:
Ich möchte lieber Kaffee (haben). = I would rather have coffee.
Wir möchten ins Kino. = We'd like to go to the movies.

Present: Er mag die Suppe. He likes the soup.
Past/Preterite: Er mochte die Stadt nicht. He didn't like the city.
Pres. Perfect/Perfekt: Er hat das Essen nicht gemocht. He didn't like the food.
Future/Futur: Er wird das schon mögen. He'll like that.
Subjunctive/Konjunktiv: Ja, er möchte Wein. Yes, he'd like (some) wine.
Subjunctive/Konjunktiv: Ich möchte... I would like...

Das mag wohl sein. That well may be. / That may be so.
Das mag der Himmel verhütten! Heaven forbid!
Er mag/mochte etwa 1,3 Meter groß sein. He must be/must have been about 1.3 meters tall.