Participles before nouns

German can pack a clause into a participle before a noun: das gelesene Buch (the book that was read), der laufende Motor (the running engine). Present participles end in -d, past participles in -t or -en.

The participle takes the adjective endings: die geschlossenen Fenster, ein überraschender Erfolg.

The extended form puts a whole phrase between the article and the noun, a habit of formal writing: die vom Lehrer korrigierten Aufgaben means the tasks that were corrected by the teacher.