高三一轮复习 专题七情态动词和虚拟语气讲解与练习

1、.专题七 情态动词和虚拟语气考点聚焦一、情态动词1、表才能表示现在有能力做某事 can be able to 表过去有能力做某事 could was/were able toEg:I am starving to death. I can eat two bowls of rice. If you have a good sleep, you will be able to work out this problem.2、 表推测可能性表示详细事情发生的可能性的层次比较词形肯定式否认式疑问式must必定、必然will很可能，大概不会，不该会.吗？would可能性比will小语气比wont弱语气

2、比will弱should按说应该ought to按说应该can不可能有可能吗？could微弱的可能不可能语气比can弱may或许、也许、也说不定可能不might比may还弱比may not还弱注：表可能性时：can/could一般用于否认句和疑问句中，表示疑惑、惊讶或不相信等，could也可用于肯定句；may/might表可能性不大，不用于疑问句；Eg:That cant be Mary, for she is in hospital.表不相信 He might be doing his homework now. They asked if we would do that again. W

3、e should arrive home before dark. You must be tired after the long journey.3、 表恳求、允许can/could表恳求：could不表过去，只表示委婉、客气的语气，但答复时必须用can.may/might表恳求：might 不表过去，仅表示语气更加委婉。will/would表恳求：用于第二人称的疑问句。shall表恳求：用于第一、三人称的疑问句。Eg:Can I use your computer for a while? -could I use your bicycle? -Yes, you can. /No, yo

4、u cant. May/might I make a suggestion? Will you help me with the luggage? Would you pay me in cash, please? Shall he come in or wait outside.4、 表必要性must 表必要性时，意为“必须dont have to/ neednt do sth,表示“表示不必要做.5、 “情态动词+have done用法一览表。1) must have done 想必/准是/一定做了 否认式：cant/couldnt have doneEg:It must have rai

5、ned last night for the road is quite muddy.2) can/could have done 本来可以做某事却没做/过去可能会做Eg:Can he have gone to his aunts?3) cannot/couldnt have done 本不可以做某事却做了/过去不可能做某事Eg:He cannot have forgotten it.他不可能忘记那件事。4) may/might have done 也许/或许已经做.一般只用于肯定句或否认句Eg:Its too late. I think he may have gone to bed. He

6、 may not have finished the work.5) should/ought to have done 本该做某事但实际上却没做Eg:You ought to have done this exercise more carefully.6) should not/ ought not to have done 本不该做某事但却做了Eg:You shouldnt have told her the truth.7) neednt have done 本不必要做某事却做了Eg:You neednt have taken a taxi here, for it was very

7、near to my house.6、 情态动词的其他用法1） cannot but do sth 表示“不得不，只好做某事Eg:I cannot but choose to go. 我只好去。2） may well/may as well“may well+动词原形,意为“完全能，很可能，相当于to be very likely toEg:He may well be proud of his son. 他大可为他的儿子感到自豪。“may as well +动词原形，意为“最好，满可以，倒不如Eg:You may as well do it at once. 你最好如今就做这件事。2、 虚拟

8、语气1、 虚拟语气在非真实条件句的应用与如今事实相反：条件句：if +主语+动词的过去式be动词用were 主句：主语+should/would/could/might+动词原形Eg:If I were you, I should seize the chance to go abroad.与过去事实相反：条件句：if+主语+had+过去分词 主句：主语+should/would/could/might+have +过去分词Eg:If you had taken my advice, you would not have failed in the exams. If+主语+动词的过去式与将来

9、事实相反：条件句 If+主语+were to +动词原形 If+主语+should +动词原形 主句：主语+should/would/could/mightEg:If he should not come tomorrow, we should put off the meeting till next Monday.2、 使用虚拟条件句时要注意以下4点：1） 错综时间条件句，动词的形式要根据它所表示的时间做出相应的调整。Eg:If you had followed my advice just now, you would be better now. If you had studied

10、hard before, you would be a college student now.2） if 省略句Eg:If I were at school again Were I at school again,I would study harder. If you had come earlier Had you come earlier, you would catch the bus. If it should rain tomorrow Should it rain tomorrow, we would not go climbing.3） 介词短语代替的条件状语从句:with

11、/without/but forEg:Without your help, we couldnt have finished the work ahead of time. But for your help, .4） 含蓄条件句Eg:I was ill that day. Otherwise, I would have taken part in the sports meeting. I should have given you more help, but I was too busy. 真题演练1. Ive ordered some pizza, so we _ worry abou

12、t cooking when we get home tired.2. It was John who broke the window. Why are you talking to me as if I _ do it.3. We would rather than our daughter _ stay at home with us, but it is her choice, and she is not a child any longer.4. My book, the house of hades, is missing. Who _ have taken it?5. I st

13、ill remember my happy childhood when my mother _ will take me to Disneyland at weekends.6. If Mr Dewey _ be present, he would have offered any possible assistance to the people there7. No one _ be more generous; he has a heart of gold.8. I _ not enjoy myself more-it was a perfect day.9. If he had sp

14、ent more time practicing speaking English before, he _ be able to speak it much better now.10. My mom suggests that we _ eat out for a change this weekend.11. Harry is feeling uncomfortable. He _ drink too much at the party last night.12. The door _ not open, no matter how hard she pushed.13. -It ra

15、ined cats and dogs this morning. Im glad we took an umbrella. 14. It _ be the vocabulary that caused you the problem in the exercise because you know a lot of words.15. He _ sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.16. Since nobody gave him any help,

16、 he _ have done the research on his own.17. -What are you doing this Saturday? -Im not sure, but I _ go to the Rolling Stones concert.18. The children _ get lost in the wood; otherwise, they would have been at the lakeside camp as a scheduled.19. I _ go to my cousins birthday party last night, but I

17、 was not available20. -Why are your eyes so red? You _ have slept well last night. -Yeah. I stayed up late writing a report.21. I should not have laughed if I _ think you were serious.22. -Do you think George has passed the driving test?-No,. If so, he _ drive his car to our college yesterday. 单句填空1

18、. -Do you like the school? -Yeah. I only wish the classes _ be a little smaller.2. According to the factory safety rules, all accidents _ be reported to the safety officer.3. One of my rules is that every student _ come to my class ahead of time.4. Its time you _ go home and Id rather you _ come aga

19、in tomorrow.5. If we _ interruptthe day before yesterday, we would have finished the project.6. Its true that being constantly exposed to advertisements is annoyed, but it _ be pleasant sometimes.7. _ I have a quick word with you? Something important has happened.8. Im really thankful to you; withou

20、t you, I _ win the first prize in the speech contest.9. Jenny certainly _ go swimming in the river- Once bitten, twice shy.10. The police still havent found the lost child, but theyre doing all they _.11. If I had known you were coming, I _ reserve a larger table.12. -I cant believe that Jeff _ have quarreled and fought with his boss. -Well, if one _ ask for trouble, it just cant be helped.