He must have finished the work by himself by the end of last month,____he?

来源：百度知道 编辑：UC知道 时间：2024/09/22 01:39:38
为什么填hadn't啊？为什么不填hasn't?为什么不填didn't?谢谢！
原句是must have ……，也就是说是现在完成时，那应该填hasn't啊，但为什么不填这个？
什么时候又可以用didn't?

hadn't he?

先要知道这句话的偏重点是must后的内容，由于by the end of last month表示在“上个月底之前”，所以描述的是“过去完成时”，即：He had finished
the work by himself by the end of last month，反义疑问句自然就是hadn't he?

前面一句用must have，就是完成时，后面就用hadn'

因为这里是have做助动词构成完成时态，而前面提到是上个月因此用hadn't
这一句是反义疑问句

He must have finished the work by himself by the end of last month,didn't_he?
此句应填didn't。因为must 后跟have finished 是对过去的推测。
我是从事英语的。不明再问啦。

把它翻译过来理解：他一定已经完成了工作，他没有完成吗？所以用过去时hadn't