高中英语外研版必修4Module 6 Unexplained Mysteries of the Nature World学案

Module 6 Unexplained Mysteries of the Nature World

情态动词＋have done的用法

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 gone to school.

约翰不在家，我想他可能去上学了吧。

You might have read about it in the newspapers.

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 she must have left here.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 gone to 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。

— Where can they have gone?

— They could have gone to 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 done better，but you were too careless.

你本来可以做得更好，但你太粗心了。

[即时训练1]　用适当的情态动词填空

①George 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.

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 watered them 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，他就不会耽误了火车。

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。

[即时训练2]　用适当的情态动词填空

①I needn't have worried before I came to the new school，for my classmates here are very friendly to me.

②—Sorry，Mum! I failed the job interview again.

—Oh，it's too bad.You should have made full preparations.

③They were abroad during the months when we were carrying out the investigation，or they would have come to our help.

Ⅰ.单句语法填空

1．He could/might have passed the exam，but he was too careless.

2．Mary can't have stolen your money.She has gone home.

3．Mr.White should have arrived at 8：30 a．m.for the meeting，but he didn't show up.

4．You needn't have woken me up; I don't have to go to work today.

5．Nobody answered the doorbell; he must have gone out.

6．He might have said so at the meeting, but I'm not sure.

7．You shouldn't have blamed the boy just now; after all，he is only a child.

8．He must have known(know) what she wanted.

9．I could have arrived here on time，but my car broke down on the way.

10．He needn't have watered(water) the flowers, but he needed to do something to kill time.

Ⅱ.单句改错

1．He was not in the office.I thought he may gone home.

 may后加have

2．— Most students in my class failed in the math test.

— It mustn't have been easy. mustn't→couldn't

3．I was really anxious about you.You couldn't have left home without a word.              couldn't→shouldn't

4．The driver must have drunk a lot before the accident，but I am not quite sure of that.              must→might

5．You should come to the meeting. What was the reason for your absence?  should后加have

6．I shouldn't have enjoyed myself more—it was a perfect day.

 shouldn't→couldn't

7．You could done it better, but you didn't try your best.

 could后加have

8．Honestly，you would have told me. would→might

9．The cake is very sweet. You must put a lot of sugar in it.

 must后加have

10．You ought have done this exercise more carefully. ought后加to