2019-2020年高中英语外研版必修4教学案：Module 6 Section Ⅲ Grammar—情态动词＋
have done的用法(含答案)
语法图解
探究发现
①Many people think the monster may be a distant cousin of the Loch Ness monster in Scotland.
②They also think that there might be similar creatures in other lakes around the world. ③But in China, the idea of the dragon may have come from the alligator. ④Youmight have givenyour parents more help earlier. ⑤Itmust have rainedlast night, for the road was quite muddy. ⑥He can't have forgottenit, for he talked about it yesterday. ⑦You ought to/should have donethe job more carefully. ⑧You oughtn't to/shouldn't have asked such a foolish question. [我的发现]
(1)①②句表示可能性的推测，意为“可能，也许”。 (2)③④句表示对过去发生的事情的推测，意为“可能已经”。
(3)⑤句表示对过去事情的很有把握的肯定推测，意为“肯定做过某事”，而⑥句则表示对过去发生事情的有把握的否定推测，意为“不可能做过某事”。
(4)⑦句表示“过去本应该做却未做的事”，⑧句则表示“过去本不该发生却发生了的事”。
1．may/might have done sth.表示对过去行为的推测，意为“也许/或许已经做过某事”，might可能性更小，主要用于肯定句和否定句中。
John isn't at home. I think he may/might have goneto school. 约翰不在家，我想他可能去上学了吧。 You might have read about it in the papers.
你可能已经在报纸上看到这个消息了。
[名师点津] might have done有时表示 “本来可以做的事而实际上没有做”，含有 “劝告，责备”的语气。
You might have been more careful. 你本来可以多加小心的。
2．must have done sth.表示对过去发生的事或行为的肯定推测，意为“一定做过某事”，只用于肯定句中。
He reasoned that since she had not answered his letter shemust have lefthere. 他推断，由于她没有给他回信，她一定是已经离开这里了。
[名师点津] 含有must have done结构的反意疑问句中，若有表示过去的时间状语，反意疑问部分用“didn't＋主语？”；若没有表示过去的时间状语，反意疑问部分则用“haven't/hasn't＋主语？”。
They must have gone there last night,didn't they? 他们昨晚一定是去那里了，不是吗？
They must have been to the Great Wall,haven't they? 他们一定去过长城，不是吗？
3．can/could have done sth.是对过去的推测，表示“可能做过某事”，主要用于否定句和疑问句中。could语气较委婉，肯定句中一般用could不用can。
Mr. Smith can't have goneto Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了，我刚才还在图书馆见过他。 — Wherecan they havegone? — They could have goneto the cinema. ——他们能去哪里呢？ ——他们可能去电影院了。
[名师点津] could have done sth.还可表示过去本可以完成而实际上未完成的动作。 You could have donebetter，but you were too careless. 你本来可以做得更好，但你太粗心了。
[即时演练1]
(1)用适当的情态动词填空
①(2016·浙江高考)George can't have gone too far.His coffee is still warm. ②—We are very worried about Tom. Why hasn't he come back? —Don't worry. He may/might have been caught in a traffic jam. ③—How did you do in the test?
—Not so well. I could have done much better but I misread the directions. ④The streets are wet. It must have rained last night. (2)完成句子
①你不可能买一辆这么昂贵的车。你肯定是从一个富朋友那里借的。
You couldn't_have_bought such an expensive car.You must_have_borrowed it from a rich friend.
②我本来可以帮助你的，但那时我太忙了。 I could_have_helped_you，but I was too busy then. ③灯还亮着，所以他不可能出去了。
The light in his room is still on, so he can't_have_gone_out. ④我房间里的手机找不到了。有可能被我姐姐拿走了。
I can't find my mobile phone in my room.It might/may_have_been_taken_away by my elder sister.
4．ought to/should have done 表示过去本来应该做某事(而实际上并没有做)，意为“理应做……，本来应该做……”，常表示遗憾；ought not to/shouldn't have done 表示“过去本来不应该做某事(而实际上做了)”，含有指责对方或自责的意味。
The flowers have died. I should have wateredthem often.
这些花儿都死了。我本来应该常给它们浇水的。(其实没浇水，表示遗憾) You ought not to have told them the truth.
你本不应该告诉他们真相的。(其实你告诉他们了，含有责备的意味)
5．needn't have done sth.表示“本来不必做某事(实际上已经做了)”； need have done sth.表示“本来需要做某事(实际上未做)”
I needn't have bought so much wine — only five people came. 我本来没有必要买这么多酒，只来了五个人。
He need have hurried to the station. In that case, he wouldn't have missed the train. 他本来需要快点去车站。那样的话，他就不会误了火车。
6．would have done sth.表示“原本想做某事”；也可以用于虚拟语气中，表示与过去事实相反。
I would have given you the book yesterday，but I didn't cover it completely. 我原本想昨天给你那本书的，可是我没能全部读完。 It would never have happened without your help. 要不是你的帮助，这绝不会发生。
[即时演练2]
(1)用适当的情态动词填空
①(2015·天津高考)I needn't have worried before I came to the new school, for my
2019-2020年高中英语外研版必修4教学案：Module 6 Section Ⅲ Grammar—情态动词+have done的用法(含答案)
