高中語法專練：ix. “can/may/might/could/must/should/need +完成式”表示對過去情況的推測

ix. “can/may/might/could/must/should/need +完成式”表示對過去情況的推測

1. “must + 完成式”意為“一定，肯定，想必，準是”,表示對過去情況進行有把握的肯定推測。

He speaks English so well, he must have been to England.

他英語說得那么好，一定去過英國。

They must have seen the film before because they know it so well.

他們以前一定看過這部電影，因為他們知道那么多。

注意其反意疑問句的反問形式：

1）有表示過去的時間狀語時，用一般過去時進行反問。謂語是must have been用wasn't/weren't反問；謂語是must have done用didn't反問。

They must have attended the meeting yesterday , didn't they ?

昨天他們一定開會了，是嗎？

They must have been to America last year, weren't they ？

去年他們一定去過美國，是嗎？

2）沒有明確的過去時間狀語時，用haven't/hasn't反問。

They must have attended the meeting, haven't they ?

他們一定參加了那次會議，是嗎？

They must have been to America, haven't they ?

他們一定去過美國，是嗎？

2. “can't/couldn't +完成式”意為“肯定沒有”，表示對過去情況進行否定推測。

She can't have gone to school, for it is Saturday today.

她肯定沒上學去，因為今天是星期六。

She couldn't have heard you knocking at the door.

她肯定沒有聽見你敲門。

注意：

1）“can +完成式”，一般只用于進行否定或疑問的推測。

There is no light in the room, can he have gone out？

房間里沒有燈光了，他可能出門了嗎？

2）“could+完成式”也表示過去能做而沒有做的事，有惋惜之意。

I could have done it better, but I had no time left.

我本來能夠做得更好，但我沒有時間了。

He could have helped you, why didn't you ask him for help?

他本來能夠幫助你的，你為什么不請他幫忙呢？

3. “may+完成式”意為“有可能已經(jīng)發(fā)生某事”，只用于對過去發(fā)生的事情進行肯定的推測。

I think he may have gone to bed.

我想他有可能已經(jīng)睡覺了。

She may have missed her train.

她有可能已經(jīng)錯過了火車。

4. “might +完成式”與“may +完成式”，二者可互換，但是might所表示的可能性較小。

—What do you think that noise was?

—It might have been a cat.

——你認為那噪音是什么？

——那或許是一只貓。

It's ten o'clock, she might have gone to bed.

現(xiàn)在十點鐘了，她或許已經(jīng)睡覺了。

注意：

might也可表示對本來可能發(fā)生卻未發(fā)生的情況感到不滿或責備。

If we had taken the other road, we might have arrived.

如果我們走另一條路，我們本來可能已經(jīng)到了。

You might have told us earlier.

你本來能早一點告訴我們的。

5. “should/ought to +完成式”，意為“本應該”，可以表示以下兩種含義：

1）過去應該做而沒做到某事，其否定式表示過去不該做而做了，有遺憾或責備之意。

You should have come here five minutes ago.

你本應該五分鐘前就到的。

We ought to have given him more help.

我們本應該給他更多的幫助的。

You shouldn't have told him the news. He is crying now.

你本不應該告訴他這個消息的，他現(xiàn)在在哭呢。

You oughtn't have gone to the football match.

你不應該去看足球的。

2）表示對現(xiàn)在應該完成的事情進行推測。

He ought to have arrived by now.

到現(xiàn)在他應該到了。

They should have finished the work by now.

到現(xiàn)在他們應該完成了工作了。

6. “needn't +完成式”，表示本來不需要做某事卻做了。

He needn't have gone to the railway station yesterday.

昨天他本來沒有必要去火車站的。

I needn't have bought all the wine—only three people came.

我本來沒有必要買這么多酒，只來了三個人。

You needn't have watered the flowers, for it is going to rain.

你本來沒有必要給花澆水的，因為天要下雨了。

專項練習

1. —You didn't hear me until now.

—No. I must _______ soundly when you came in.

A. have been sleeping

B. have slept

C. be sleeping

D. sleep

2. Her father thought that she _______ a fairy.

A. must have met

B. had to have met

C. must meet

D. must had met

3. He must have lost the key the day before yesterday, _______?

A. must he

B. hasn't he

C. needn't he

D. didn't he

4. They _______ have gone out because the light is on.

A. mustn't

B. can't

C. may not

D. isn't able to

5. We didn't see him at the lecture yesterday. He _______ it.

A. oughtn't

B. can't have attended

C. couldn't attend

D. needn't have attended

6. She is very careful. How _______ she _______ such a mistake the day before yesterday?

A. could; have made

B. should; have made

C. could; has made

D. can; made

7. He is my good friend. I am sure that he _______ ill of me that day.

A. couldn't have spoken

B. mightn't have spoken

C. must have spoken

D. couldn't have to speak

8. I was writing my report last Sunday. Otherwise, I _______ you to the zoo.

A. would take

B. took

C. should take

D. could have taken

9. —Have you found your book yet?

—No, I'm not sure where I _______ it.

A. must have left

B. might leave

C. could have left

D. can leave

10. He _______ the truth. Otherwise he might have known it was Tom who had taken his place.

A. should have been told

B. shouldn't have been told

C. couldn't have been told

D. must have been told

11. Mr. Bush is on time for everything. How _______ it have been that he was late for the opening ceremony?

A. could

B. should

C. may

D. must

12. —I stayed at a hotel while in New York.

—Oh, did you? You _______ with Barbara.

A. could have stayed

B. could stay

C. would stay

D. must have stayed

13. He _______ you more help, even though he was very busy.

A. might have given

B. might give

C. may have given

D. may give

14. —He was here yesterday, but no one has seen him since.

—He _______ an accident.

A. might have

B. might have had

C. can have

D. mustn't have had

15. You were stupid to try climbing up there. You _______ yourself.

A. might have killed

B. should have killed

C. must have killed

D. can't have killed

16. The plant is dead. I _______ it more water.

A. will give

B. would have given

C. must give

D. should have given

17. I told Sally how to get here, but perhaps I _______ for her.

A. had to write it out

B. must have written it out

C. should have written it out

D. ought to write it out

18. That young man has made so much noise that he _______ not have been allowed to attend the concert.

A. could

B. must

C. would

D. should

19. There was a lot of fun at yesterday's party. You _______ come, but why didn't you?

A. must have

B. should

C. need have

D. ought to have

20. I'm sorry. I _______ to tell you I was coming.

A. ought to phone

B. should phone

C. need to phone

D. ought to have phoned

21. We _______ the letter yesterday, but it didn't arrive.

A. must receive

B. ought to receive

C. must have received

D. ought to have received

22. When I got to the cinema, the film had already started; I _______ there earlier.

A. ought to get

B. ought to have got

C. must have got

D. must get

23. The old lady _______.

A. ought to apologize to

B. ought to be apologized to

C. ought apologize to

D. ought be apologized to

24. You oughtn't to have helped him with his English, _______?

A. won't you

B. ought not you

C. oughtn't you

D. wouldn't you

25. Although he had made many mistakes in his composition, _______ have laughed at him?

A. oughtn't we

B. should we

C. oughtn't to we

D. ought to we

26. He didn't do well in the exam. He _______ hard at his lessons.

A. must have worked

B. ought to have worked

C. would have worked

D. has worked

27. —I didn't go to see a doctor yesterday.

—But you _______.

A. ought to

B. ought to go

C. should

D. ought to have

28. He began to write two hours ago. He _______ have finished the article by now.

A. must

B. ought to

C. ought

D. had to

29. One ought _______ for what one hasn't done.

A. not to be punished

B. to not be punished

C. to not punished

D. not be punished

30. He _______ the meeting, so he stayed at home.

A. needn't have attended

B. didn't need to attend

C. didn't need attend

D. needn't to have attended

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