Question

The room must have been cleaned yesterday,wasn't it?为什么表示一种状态？

Answer 1

The room must have been cleaned yesterday,wasn't it?
为什么表示一种状态？
这个不是表示一种状态，而是一个被动的动作。
must have+过去分词：表示对已发生的动作或状态推测。译为：肯定已经
如果加过去时间状语，反义问句就用一般过去时。
He must have cleaned the room, hasn't he?
He must have cleaned the room yesterday, didn't he?
这是主动语态。
被动：
The room must have been cleaned yesterday, wasn't he?

追问

表动作的话，为什么不用did？

追答

被动语态有没有did的。
The work was done yesterday, wasn't it?

追问

Mr Green must have been punished for his being rude at the meeting,didn‘t he？这句话为什么正确呢？

追答

Mr Green must have been punished for his being rude at the meeting,didn't he？
这句话是错句。应该用wasn't he