透析高考英語語法專題—情態(tài)動詞和虛擬語氣

1、透析高考英語語法專題情態(tài)動詞和虛擬語氣一、 情態(tài)動詞的語法特征：1、 情態(tài)動詞不能表示正在發(fā)生或已經(jīng)發(fā)生的事情，只表示期待或估計某事的發(fā)生。2、 情態(tài)動詞除ought 和have外，后面只能接不帶 to 的不定式。3、 情態(tài)動詞沒有人稱、數(shù)的變化。4、 情態(tài)動詞沒有非謂語形式。二、虛擬語氣用來表示說話人的主觀愿望或假想，所說的是一個條件，多半不是事實，或與事實相反。 高考重點要求：1、情態(tài)動詞的基本用法2、情態(tài)動詞表示推測的語義差別3、情態(tài)動詞后接不定式完成體的不同意義4、虛擬語氣中情態(tài)動詞的用法情態(tài)動詞 (一) 情態(tài)動詞在一般時否定句中的用法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”，“不許可”，needn't (need not) 表示“不必”，dare not 動詞原形表示“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三者用法比較來源: can，may，must是三

3、個最重要的情態(tài)動詞，其基本句型如下：肯定句：主語+can，may，must +動詞原形否定句：主語+can，may，must +not +動詞原形疑問句：Can，May，Must +主語+動詞原形1. can，may，must的肯定句You may eat lunch，but you must wash your hands. 你可以吃飯，但是你必須洗手。（1）can表示能力；能，會 She can run fast，but I can't. 她很會跑，但是我不會。表示可能；能夠 I can get there in ten minutes. 我十分鐘之后就可以到那兒。（表示一種可能性

4、）表示允許；許可 You can use this dictionary. 你可以用這本字典。can和be able to比較can只有現(xiàn)在式和過去式，而be able to可以用于各種時態(tài)。can（could）表示能力時，可用be able to代替。I can（=am able to）pay for the book.           我買得起那本書。He will be able to tell you the news soon.    

5、60;    他很快就能告訴你消息了。She has been able to come to school.              她已經(jīng)能去學(xué)校了。（2）may表示請求、許可 May I borrow your pen？ 我可以借你的鋼筆用一用嗎？可能、或許 Tomorrow I may go shopping. 明天，我可能（或許）去商店買東西。He might be our new teacher. 他或許是我們的新老師。（

6、3）must必須、應(yīng)該（表示有做某一動作的必要或義務(wù)） You must buy a ticket. 你必須買一張票。一定、準是（表示有把握的判斷或推測，一般只用于肯定句中）He must be our new teacher. 他肯定是我們的新老師。表示推測的用法can , could ,may ,might ,must 皆可用來表示推測，其用法如下：could ,might 表示推測時不表示時態(tài)，其推測的程度不如can ,may。can ,could 用于否定句和疑問句中。句型：主語+ can't , couldn't +be +v-ing（否定句）Can ,Could +

7、主語 +be +v-ing（疑問句）They can't be cleaning the room now他們現(xiàn)在不可能在打掃房間。may ,might , must 用在肯定句中。句型：主語+ may ,might ,must +be +動詞 -ing （表示對現(xiàn)在發(fā)生動作的推測）He must be sleeping . 他現(xiàn)在肯定在睡覺。must /can't + have +過去分詞則指對過去已發(fā)生的事進行推測。The road is wet. It must have rained last night . 地是濕的；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 +動詞原形have（has）to后面要用動詞原形。當主語為第三人稱單數(shù)時用has to，當句子是過去時用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、語+don't（doesn't, didnt, will not）have to+動詞原形You don't have to walk so fast.He will not have to buy a new coat next year.3. have to的疑問句你現(xiàn)在必須學(xué)數(shù)字嗎？ _ .Yes，I _. No，I _（have to）。他非要問那個問題嗎？ Did he have to ask the question？Yes，he did. No，he didn't（have to）4. must與have to比較must側(cè)重于個人意志和主觀上的必

10、要，have to側(cè)重于客觀上的必要。如果用于過去時態(tài)或?qū)頃r態(tài)時，則要用have to的相應(yīng)時態(tài)來代替must。但must可用于間接引語中表示過去的必要或義務(wù)。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.他說他們必須努力工作。(四). used to do

11、 sth 的用法 注意其否定句和疑問句的結(jié)構(gòu)。 There used to be a lot of trees here,_ ?虛擬語氣 虛擬語氣表示說話人的意愿、假設(shè)、猜測或建議。虛擬語氣不表示客觀存在的事實，謂語動詞用特殊的形式表示虛擬語氣。1 表示與現(xiàn)在事實相反時的謂語形式。從句主句過去式 (be和were)would (should、could)+ 動詞原形例如：If Tom were hungry, he would eat the bread. (In fact, Tom isnt hungry.)2 表示與過去事實相反的謂語形式。從句主句had + 過去分詞would (shou

12、ld、could) + have +過去分詞例如：If I had left a little earlier, I would have caught the early bus. (In fact, I didnt catch the bus.)3 表示與將來事實相反的謂語形式。 從句主句動詞過去式should + 動詞原形were to + 動詞原形would (should、could) + 動詞原形例如：If they came tomorrow, we would told them about it. (In fact, they wont come tomorrow。)來源:

13、4 動詞wish后的賓語從句中，謂語動詞可用過去式、過去完成式或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 在有些動詞，常見的有：一個“堅持”（insist）,二個“命令”（order,command）,三個“建議”（suggest,advise,propose）,四個“要求”（demand,require,request,ask）后的賓語從句中謂語動詞用“should + 動詞原

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從句中的謂語動詞用should + 動詞原形，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句式中從句謂語動詞用過去式。例如：It is

15、time we went to bed.I would rather he came next week.復(fù)習(xí)時需注意的要點（一）情態(tài)動詞1、情態(tài)動詞在句中沒有人稱和數(shù)的變化。2、含有情態(tài)動詞的句子改為否定句或疑問句不必加助動詞，只需要將情態(tài)動詞置于主語前，或在情態(tài)動詞后加上not。e.g. Must I write a letter to cheer him up?You neednt wait for me.3、 情態(tài)動詞的過去式，例如cancould，maymight。但是少數(shù)情態(tài)動詞只有過去式，例如used to表示過去常常。must的過去式往往用had to代替。4、 情態(tài)動詞后還可

16、接不定式的進行式、完成式和被動式。e.g.He cant be doing his homework now. He must have attended the meeting last night.（二）虛擬語氣1、 在if條件句中，如果含有were , should或had等助動詞，if可以省去，句子用倒裝。e.g. Were I you , I would buy this reference book.(=_)2、 should與would都可以用于if條件句的主句中，但should一般只用于第一人稱，would用于所有人稱。e.g. If you were here , I wou

17、ld tell you the news .3、 某些條件可以用介詞短語without , but for 等來表示 。e.g. Without your help , I could not have succeeded in passing the exam .4、 有時句子通過but或otherwise等詞來表示真實與虛擬的轉(zhuǎn)換，在這種情況下，只有不真實的部分用虛擬式。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等詞的相應(yīng)的名詞組成的同位語從句及表語從句用虛擬式。來源: e.g. I accepted my mothers suggestion that I should eat an apple every day . 二、歷屆高考試題分析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鞏固練習(xí)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 來源: 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.