Ответ:
1) вопросительный: Are there five chairs in the room? отрицательная: There aren't five chairs in the room
2) вопросительный: Did I read this book last year? отрицательная: I didn't read this book last year.
3) вопросительный: Does she usually have dinner at 6 o'clock отрицательная: she doesn't usually have dinner at 6 o'clock
4) вопросительный: Is Ann twenty years old? отрицательная: Ann isn't twenty years old.
5) вопросительный: Do they speak German fluently? отрицательная: They don't speak German fluently