UC知道must have done的反意疑问句问题
来源：百度知道 编辑：UC知道 时间：2024/05/31 00:01:55
He must have finished his homework yesterday afternoon,didn’t he?
must have done本身就已经是对过去发生的是进行猜测了，为什么还有加不加yesterday afternoon的区别呢，为什么不加的就是强调现在的结果，而加的就是强调过去呢？请那位高手解释一下好吗？谢谢！！
答案应该是didn't he
一、对现在情况的推测，问句部分用主动词（do,be)一般现在时的适当形式。若是现在进行时，问句部分用现在进行时的适当形式表示。若是there be结构，问句用isn't/aren't there。如：
1)He must be there,isn't he?
2)He must have a big family,doesn't he?
3)He must be waiting outside,isn't he?
4)There must be some students in the room,aren't there?
二、对已发生的过去情况的推测，若陈述句谓语部分有“must have done”，而且有表示过去的时间状语，问句部分用didn't；若没有表示过去的时间状语，问句部分用haven't或hasn't。如：
1)They must have gone there last night,didn't they?
2)They must have arrived by now,haven't they?（根据by now来判断）
3)They must have been to the Great Wall,haven't they?
三、若是被动，应按被动结构来处理。如：
1)The room must have been cleaned yesterday,wasn't it?
2)The room must have been cleaned,hasn't it?
四、若句中有表示过去完成时的时间状语，问句部分应用hadn't.如:
They must have learnt 5000 English words by the end of last term,hadn't they?
(本题中must表推测，如果将它去掉，还原为真实句就是They had learn