What is the direct object of a sentence?
The direct object is the not-acting person / thing in a sentence. The direct object receives the action of theverb.
Der Mann küsst die Frau.
The man is doing something. He kisses the woman. So the man is the subject of the sentence (=nominativecase).The woman is being kissed. She is not acting. So she is the direct object (=accusative case).