you must······,1 must 做必须讲的话,musn't you?
2 做 一定（表示猜测）讲,复杂了 根据具体时间对应时态.
you must be at home,aren't you?
you must be at home yesterday,weren't you?
you must have finished yourhomework,haven't you?
you must have finished your homework yesterday,didn't you?
祈使句的反义疑问句,除了 Let's ...,shall we?,其他 will you?