Complex sentence: His mother prays for him, knowing it will only be a matter of time before the authorities come and take him away to serve Hitler, a Nazi officer bangs on the door to take Hans away, but his mother says he is sick and needs care.
Split into simpler sentences: His mother prays for him, knowing it will only be a matter of time before the authorities come and take him away to serve Hitler. A Nazi officer bangs on the door to take Hans away, but his mother says he is sick and needs care.