透析高考英语语法专题—情态动词和虚拟语气

1、透析高考英语语法专题情态动词和虚拟语气一、 情态动词的语法特征：1、 情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。2、 情态动词除ought 和have外，后面只能接不带 to 的不定式。3、 情态动词没有人称、数的变化。4、 情态动词没有非谓语形式。二、虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，多半不是事实，或与事实相反。 高考重点要求：1、情态动词的基本用法2、情态动词表示推测的语义差别3、情态动词后接不定式完成体的不同意义4、虚拟语气中情态动词的用法情态动词 (一) 情态动词在一般时否定句中的用法can't(cannot) 表示“不可能”

2、， may not 表示“不可以”， mustn't(must not) 表示“一定不要”，“不许可”，needn't (need not) 表示“不必”，dare not 动词原形表示“不敢”。He can't know the news. He may not sleep now. You mustn't criticize her in that way. You needn't come tomorrow. He dared not meet his parents. （二）can，may，must三者用法比较来源: can，may，must是三

3、个最重要的情态动词，其基本句型如下：肯定句：主语+can，may，must +动词原形否定句：主语+can，may，must +not +动词原形疑问句：Can，May，Must +主语+动词原形1. can，may，must的肯定句You may eat lunch，but you must wash your hands. 你可以吃饭，但是你必须洗手。（1）can表示能力；能，会 She can run fast，but I can't. 她很会跑，但是我不会。表示可能；能够 I can get there in ten minutes. 我十分钟之后就可以到那儿。（表示一种可能性

4、）表示允许；许可 You can use this dictionary. 你可以用这本字典。can和be able to比较can只有现在式和过去式，而be able to可以用于各种时态。can（could）表示能力时，可用be able to代替。I can（=am able to）pay for the book.           我买得起那本书。He will be able to tell you the news soon.    

5、60;    他很快就能告诉你消息了。She has been able to come to school.              她已经能去学校了。（2）may表示请求、许可 May I borrow your pen？ 我可以借你的钢笔用一用吗？可能、或许 Tomorrow I may go shopping. 明天，我可能（或许）去商店买东西。He might be our new teacher. 他或许是我们的新老师。（

6、3）must必须、应该（表示有做某一动作的必要或义务） You must buy a ticket. 你必须买一张票。一定、准是（表示有把握的判断或推测，一般只用于肯定句中）He must be our new teacher. 他肯定是我们的新老师。表示推测的用法can , could ,may ,might ,must 皆可用来表示推测，其用法如下：could ,might 表示推测时不表示时态，其推测的程度不如can ,may。can ,could 用于否定句和疑问句中。句型：主语+ can't , couldn't +be +v-ing（否定句）Can ,Could +

7、主语 +be +v-ing（疑问句）They can't be cleaning the room now他们现在不可能在打扫房间。may ,might , must 用在肯定句中。句型：主语+ may ,might ,must +be +动词 -ing （表示对现在发生动作的推测）He must be sleeping . 他现在肯定在睡觉。must /can't + have +过去分词则指对过去已发生的事进行推测。The road is wet. It must have rained last night . 地是湿的；昨天晚上肯定下雨了。There isn't

8、 any water on the road . It (can't ) couldn't have rained last night .You must have seen the film,_ you?(三) have to的用法1. have（has）to +动词原形have（has）to后面要用动词原形。当主语为第三人称单数时用has to，当句子是过去时用had to。We have to leave now.He has to work on Sunday.I had to do my homework last Sunday.2. have to的否定句句型：主

9、语+don't（doesn't, didnt, will not）have to+动词原形You don't have to walk so fast.He will not have to buy a new coat next year.3. have to的疑问句你现在必须学数字吗？ _ .Yes，I _. No，I _（have to）。他非要问那个问题吗？ Did he have to ask the question？Yes，he did. No，he didn't（have to）4. must与have to比较must侧重于个人意志和主观上的必

10、要，have to侧重于客观上的必要。如果用于过去时态或将来时态时，则要用have to的相应时态来代替must。但must可用于间接引语中表示过去的必要或义务。My brother was very ill，so I _call for the doctor in the middle of the night.I haven't got any money with me，so I'll have to borrow some from my friend.He said that they must work hard.他说他们必须努力工作。(四). used to do

11、 sth 的用法 注意其否定句和疑问句的结构。 There used to be a lot of trees here,_ ?虚拟语气 虚拟语气表示说话人的意愿、假设、猜测或建议。虚拟语气不表示客观存在的事实，谓语动词用特殊的形式表示虚拟语气。1 表示与现在事实相反时的谓语形式。从句主句过去式 (be和were)would (should、could)+ 动词原形例如：If Tom were hungry, he would eat the bread. (In fact, Tom isnt hungry.)2 表示与过去事实相反的谓语形式。从句主句had + 过去分词would (shou

12、ld、could) + have +过去分词例如：If I had left a little earlier, I would have caught the early bus. (In fact, I didnt catch the bus.)3 表示与将来事实相反的谓语形式。 从句主句动词过去式should + 动词原形were to + 动词原形would (should、could) + 动词原形例如：If they came tomorrow, we would told them about it. (In fact, they wont come tomorrow。)来源:

13、4 动词wish后的宾语从句中，谓语动词可用过去式、过去完成式或would、might加原形。例如：I wish I were as strong as you.He wished I would stay with us.She wished I had attended the meeting yesterday.5 在有些动词，常见的有：一个“坚持”（insist）,二个“命令”（order,command）,三个“建议”（suggest,advise,propose）,四个“要求”（demand,require,request,ask）后的宾语从句中谓语动词用“should + 动词原

14、形”，should可以省略。例如：He suggested that we (should) discuss the problem right now.6 在有些句型中如：It is important (necessary、natural、strange等) + that从句中的谓语动词用should + 动词原形，should可以省略。例如：It is necessary that the doctor (should) be sent there at once.7 在It is time that, I would rather that句式中从句谓语动词用过去式。例如：It is

15、time we went to bed.I would rather he came next week.复习时需注意的要点（一）情态动词1、情态动词在句中没有人称和数的变化。2、含有情态动词的句子改为否定句或疑问句不必加助动词，只需要将情态动词置于主语前，或在情态动词后加上not。e.g. Must I write a letter to cheer him up?You neednt wait for me.3、 情态动词的过去式，例如cancould，maymight。但是少数情态动词只有过去式，例如used to表示过去常常。must的过去式往往用had to代替。4、 情态动词后还可

16、接不定式的进行式、完成式和被动式。e.g.He cant be doing his homework now. He must have attended the meeting last night.（二）虚拟语气1、 在if条件句中，如果含有were , should或had等助动词，if可以省去，句子用倒装。e.g. Were I you , I would buy this reference book.(=_)2、 should与would都可以用于if条件句的主句中，但should一般只用于第一人称，would用于所有人称。e.g. If you were here , I wou

17、ld tell you the news .3、 某些条件可以用介词短语without , but for 等来表示 。e.g. Without your help , I could not have succeeded in passing the exam .4、 有时句子通过but或otherwise等词来表示真实与虚拟的转换，在这种情况下，只有不真实的部分用虚拟式。e.g. I was ill yesterday；otherwise I would have played football with you . But for the heavy rain , we would ha

18、ve gone to the concert .5、 有suggest等词的相应的名词组成的同位语从句及表语从句用虚拟式。来源: e.g. I accepted my mothers suggestion that I should eat an apple every day . 二、历届高考试题分析1、There _ be any difficulty about passing the road test since you have practised a lot in the driving school. A. mustnt B. shant C. shouldnt D. need

19、nt 2、Is John coming by train? He should, but he _ not. He likes driving his car.A. must B. can C. need D. may3、It is hard for me to imagine what I would be doing today if I _ in love, at the age of seven, with the Melinda Cox Library in my hometown.A. wouldn't have fallen B. had not fallen C. sh

20、ould fall D. were to fall4、You can't imagine that a well-behaved gentleman _be so rude to a lady.A. might B. need C. should D. would5、What would have happened _, as far as up to the river bank?A. Bob had walked farther B. if Bob should walk fartherC. had Bob walked farther D. if Bob walked farth

21、er6、Mr. Bush is on time for everything. How _it be that he was late for the opening ceremony?A. can B. should C. may D. must7、My sister met him at the Grand Theatre yesterday afternoon, so he _ your lecture.A. couldn't have attended B. needn't have attendedC. mustn't have attended D. sho

22、uldn't have attended8、He hesitated for a moment before kicking the ball, otherwise he_ a goal.A. had scored B. scored C. would score D. would have scored9、Oh, I'm not feeling well in the stomach. I _ so much fried chicken just now.A. shouldn't eat B. mustn't have eaten C. shouldn'

23、;t have eaten D. mustn't eaten10、I was really anxious about you .You_ home without a word.A. mustn't leave B. shouldn't have left C. couldn't have left D. needn't leave巩固练习1. Isn' t that Ann's husband over there?No, it _ be him . I'm sure he doesn't wear glasses.A

24、. can't  B. must not C. won't   D. may not2.You to the meeting this afternoon if you have something important to do.A. needn't to comeB. don't need come C. don't need comingD. needn't come 3. He you more help, even though he was very busy. A. might have given B

25、. might give C. may have givenD. may give 4. The reason why they leave wasn't explained to us. A. had B. had to C. must D. might 5. I searched for my wallet and it wasn't there. I thought I it at home.A. left B. have left C. might have left D. could have left 来源: 6. I _ asleep because it too

26、k me a long time to realize that the telephone was ringing.A. could have fallen B. should have fallen C. must have fallen D. mustn't have fallen 7. The only thing that really matters to the children is how soon they return to their school. A. can B. must C. have to D. ought to 8. I want to go to

27、 the chemist's, but you go with me. A. need not B. must not C. need D. cant9. What we get seems better than what we have. A. can B. could C. can't D. couldn't 10. My goodness! I've just missed the train. That's too bad. I am sure you it, if you had hurried. A. could have caught B

28、. had caught C. would catch D. could catch 11. Look! What you've done! You more careful.A. may be B. had toC. should have been D. would be 12. I repeat the question? A. Shall B. Will C. Do you want that D. Do 13. Professor Li, many students want to see you. they wait here or outside!A. Do B. Wil

29、l C. Shall D. Are 14. You read that book if you don't want to. A. haven't B. can't C. mustn't D. needn't 15. Johnny, you play with the knife; you hurt yourself.A. won't can't B. can'tshouldn't C. shouldn'tmust D. mustn'tmay16. There were already 5 people i

30、n the car, but they managed to take me as well. It a comfortable journey. A. can't beB. shouldn't beC. couldn't have been D. mustn't have been 17. Tom ought not to me your secret, but he meant no harm.A. have told B. tellC. be telling C. having told 18. Everyone is here. we start the

31、 meeting? A. Can B. Must C. Should D. Shall 19. I parked my car right here but now it's gone. It .A. must be stolen B. may be stolenC. must have stolen D. must have been stolen 20. He the work yesterday, but he didn't.A. must have finished B. need have finished C. finishedD. should have fini

32、shed 21. He did not pass the examination. As a good student, he . A. mustn't have failed B. may not have failed C. needn't have failed D. shouldn't have failed 22. it be true that Albert passed the test in geography? A. MayB. Should C. Could D. Would 23. You lead a horse to the water but

33、 you not make it drink. A. willcan B. maycanC. maydare D. darecan 24. Must we finish the composition in class? No, you . A. needn't B. mustn'tC. won't D. shouldn't 25. Her eyes were red. She . A. must cry B. must be cried C. must have been crying D. may cry 26. Mary his letter; other

34、wise she would have replied before now. A. has received B. must receive C. couldn't have received D. shouldn't have received 27. 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 out28. He described the town as if he it himself. A. had seen B. has seen C. saw D. sees 29.