(intransitive) to occur; to happen / (intransitive, with mit or with bare dative) to happen to (someone) / (impersonal, with dative and recht) to serve (someone) right (in this construction passieren is not possible)

past participle of geschehen / over, lost, done for, doomed, dead

what is happening, what is going on / events, happenings

no use crying over spilt milk. / what's done is done

You're welcome: a response to an expression of thanks. / It's a pleasure.

present participle of geschehen

genitive singular of Geschehen