1. dürfen (to be permitted, may)
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...
NOTE: For all modals with umlauts, the simple past (preterite/Imperfekt) has no umlaut, but the subjunctive form always has an umlaut!
Sample Idiomatic Expressions:
Was darf es sein? May I help you? (store clerk)
Wenn ich bitten darf. If you please.