專四語法第7節(jié)--情態(tài)助動詞

1、專四語法專題第七節(jié)：情態(tài)助動詞I. 情態(tài)助動詞考點和知識要點：情態(tài)助動詞概述：情態(tài)助動詞有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等。 情態(tài)動詞無人稱和數(shù)的變化；不能單獨使用，必須與其后的動詞原形構(gòu)成謂語。情態(tài)助動詞知識要點：1. can / could2. may / might3. will, would4. shall5. should, ought to6. must7. need8. dare9. 情態(tài)動詞+不定

2、式完成式have done1. can / could1) 表示請求和允許(Permission) -Can I go now?- Yes, you can. / No, you cant.此時可與may互換。在疑問句中還可用could,might代替，不是過去式，只是語氣更委婉，不能用于肯定句和答語中。- Could I come to see you tomorrow?- Yes, you can. ( No, Im afraid not. )2) 表示能力體力、知識、技能(Ability)Can you lift this heavy box?體力Mary can speak three

3、 languages.知識Can you skate?技能表示“能力”時可與be able to互換。Can只有一般現(xiàn)在時和一般過去式；而be able to則有更多的時態(tài)。Ill not be able to come this afternoon.但當表示“經(jīng)過努力才得以做成功某事”時應(yīng)用be able to，不能用Can。如：He was able to go to the party yesterday evening in spite of the heavy rain.3) 表示客觀可能性客觀原因形成的能力(Possibility)Theyve changed the timeta

4、ble, so we can go by bus instead.This hall can hold 500 people at least.4) 表示推測驚訝、疑心、不相信的態(tài)度，用于疑問句、否認句和感慨句中。Can this be true?This cant be done by him.How can this be true?2. may / might 1) 表示請求和允許(Permission)。might比 may語氣更委婉，而不是過去式。否認答復(fù)時可用cant或mustnt，表示“不可以，禁止”。 -Might/ May I smoke in this room? - No

5、, you mustnt. - May/Might I take this book out of the room? - Yes, you can. (No, you cant / mustnt. ) 用May I.？征徇對方許可時比較正式和客氣，而用Can I.？在口語中更常見。2表示推測、可能性不用于疑問句(Possibility)。 might不是過去式，它所表示的可能性比may小。 He may /might be very busy now. Your mother may /might not know the truth.3) 用于祈使句，表示祝愿。 May you succe

6、ed!4) may /might.as well表示“不妨，還是.的好”,也可以寫作may /might as well. Since it is raining hard, you may as well stay here.3. will, would 1) 用于第二人稱疑問句中，表示請求、建議等，would更委婉，不表時態(tài)。Will / Would you pass me the ball, please?2) 表示意愿Willingness、意圖Intention、決心Determination、承諾Promise等，可用于各種人稱。I will never do that again

7、.They asked him if he would go abroad.3) would表示過去反復(fù)發(fā)生的動作或某種傾向。would表示過去習慣時比used to正式，且沒有“現(xiàn)已無此習慣”的含義。During the vacation, he would visit me every other day.The wound would not heal.4) 表示估計和猜想。It would be about ten oclock when she left home.4. shall 1) shall 用于第一人稱，征求對方的意見。What shall we do this eveni

8、ng?2) shall 用于第二、三人稱，表示說話人給對方的命令、警告、允諾或威脅。You shall fail if you dont work hard.(警告)He shall have the book when I finish it.(允諾)He shall be punished.(威脅)5. should, ought to 1) should, ought to表示“應(yīng)該”，ought to表示義務(wù)或責任，比should語氣重。I should help her because she is in trouble.You ought to take care of the b

9、aby.2) 表示勸告、建議和命令。should, ought to可通用，但在疑問句中常用should。You should / ought to go to class right away.Should I open the window?3) 表示推測 should , ought to (客觀推測), must(主觀推測)。He must be home by now. (斷定他已到家)He ought to/should be home by now.(不太肯定)This is where the oil must be.(直爽)This is where the oil ough

10、t to/should be.(含蓄) Uncertain might may could can should ought to would willCertain must 6. must, have to 1) 表示必須、必要。You must come in time.在答復(fù)引出的問句時，如果是否認的，不能用mustnt禁止，不準，而用neednt, dont have to不必.- Must we hand in our exercise books today?- Yes, you must.- No, you dont have to / you neednt. 2) must是

11、說話人的主觀看法， 而have to則強調(diào)客觀需要。Must只有一般現(xiàn)在時， have to 有更多的時態(tài)形式。 He play isnt interesting, I really must go now. I had to work when I was your age. 3) 表示推測、可能性只用于肯定的陳述句 Youre Toms good friend, so you must know what he likes best. Your mother must be waiting for you now.7. dare, need 1) dare作情態(tài)動詞用時, 常用于疑問句、否

12、認句和條件從句中, 過去式形式為dared。 How dare you say Im unfair? He darent speak English before such a crowd, dare he? If we dared not go there that day， we couldnt get the beautiful flowers.2) need 作情態(tài)動詞用時, 常用于疑問句、否認句。在肯定句中一般用must, have to, ought to, should代替。 You neednt come so early. - Need I finish the work t

13、oday? - Yes, you must. / No, you neednt. 3) dare和 need作實義動詞用時， 有人稱、時態(tài)和數(shù)的變化。在肯定句中，dare后面常接帶to的不定式。在疑問句和否認句中，dare后面可接帶to或不帶to的不定式。而need后面只能接帶to的不定式。 I dare to swim across this river. He doesnt dare (to) answer. He needs to finish his homework today. 8. will, would 1) 用于第二人稱疑問句中，表示請求、建議等，would更委婉，不表時態(tài)。

14、Will / Would you pass me the ball, please?2) 表示意愿Willingness、意圖Intention、決心Determination、承諾Promise等，可用于各種人稱。I will never do that again.They asked him if he would go abroad.3) would表示過去反復(fù)發(fā)生的動作或某種傾向。would表示過去習慣時比used to正式，且沒有“現(xiàn)已無此習慣”的含義。During the vacation, he would visit me every other day.The wound

15、would not heal.4) 表示估計和猜想。It would be about ten oclock when she left home. 9. 情態(tài)動詞+不定式完成式have done 1) can / could + have done在肯定句中表示“本來可以做而實際上能做某事”，是虛擬語氣；在疑問句或否認句中表示對過去行為的疑心或不肯定, 表示推測。You could have done better, but you didnt try your best. 虛擬語氣He cant have been to that town.推測Can he have got the bo

16、ok?推測2) may / might +不定式完成式have done表示對過去行為的推測。不能用于疑問句中，沒有虛擬語氣的用法。Might所表示的可能性比may小。He may not have finished the work .If we had taken the other road, we might have arrived earlier. 3must +不定式完成式have done用于肯定句中，表示對過去行為的推測。意為“一定、想必”。其疑問、否認形式用can，cant代替。參看1) can / could + have done表示推測。You must have s

17、een the film Titanic.He must have been to Shanghai.4should +不定式完成式have done 用于肯定句中，表示對過去行為的推測。 He should have finished the work by now。 表示“本應(yīng)該做而實際上沒有做某事”，其否認式表示某種行為本不該發(fā)生卻發(fā)生了可以與ought to +不定式完成式have done互換。You ought to / should have helped him. (but you didnt.)She shouldnt have taken away my measuring

18、 tape, for I wanted to use it.5) neednt +不定式完成式have done表示“本來不必做而實際上做了某事”。You neednt have watered the flowers, for it is going to rain.6) will +不定式完成式have done主要用于第二、三人稱，表示對已完成的動作或事態(tài)的推測。He will have arrived by now.II. 情態(tài)助動詞專四真題模擬題1. Among the four sentences below, Sentence _ expresses the

19、highest degree of possibility.A. It may take a long time to find a solution to the problem.B. It might take a long time to find a solution to the problem.C. It could take a long time to find a solution to the problem.D. It should take a long time to find a solution to the problem.2. Which of the fol

20、lowing italicized words does NOT indicate willingness?A. What will you do when you graduate?B. They will be home by now.C. Who will go with me?D. Why will you go there alone?3. When the sentence “Shall I drive you to the airport first?” is turned into indirect speech, which of the following is most

21、appropriate? A. He agreed to drive me to the airport first. B. B. He offered to drive me to the airport first. C. He advised me to go to the airport first. D. He suggested that I drive to the airport first.4. Which of the following sentences indicates POSSIBILITY?A. The moon cannot always be at the

22、full.B. You cannot smoke inside the building.C. He cannot come today.D. She cannot play the piano.5. Which of the following sentences a fact? A. Mary and her son must be home by now. B. Careless reading must give poor results. C. He must be working late at the office.DIts getting late, and I must le

23、ave now.6. Which of the following best explains the meaning of "Shall we buy the tickets first”? AHe said that we were going to buy the tickets first BHe requested that we buy the tickets first CHe suggested that we buy the tickets first DHe advised us to buy the tickets first7. Which of the fo

24、llowing sentences expresses WILLINGNESS? ABy now she will be eating dinner BI shall never do that again CMy brother will help you with the luggage DYou shall get a promotion8. The sentence that expresses OFFER is _.A. I'll get some drinks. What'll you have? B. Does she need to book a ticket

25、now?C. May I know your name? D. Can you return the book next week?9. Nancy's gone to work but her car's still there. She _ by bus.A. must have gone B. should have goneC. ought to have gone D. could have gone10. Arent you tired? I _ you had done enough for today.A. should have thought B. must

26、 have thoughtC. might have thought D. could have thought11. ，A. must take B. must have madeC. was able to make D. could make12. Which of the following sentences expresses "probability"?A. You must leave immediately.B. You must be feeling rather tired.C. You must be here by eight o'cloc

27、k.D. You must complete the reading assignment on time.13. She _fifty or so when I first met her at the conference.A. must be B. had been C. could be D. must have been14. You _ borrow my notes provided you take care of them, I told my friend.A. could B. should C. must D. can15. I am surprised_ this c

28、ity is a dull place to live in.A. that you should think B. by what you are thinkingC. that you would think D. with what you were thinking16. Loud speakers were fixed in the hall so that everyone_ an opportunity to hear the speech.A. ought to have B. must have C. may have D. should have17. You _ anyt

29、hing about it. It was none of his business.a. neednt have told b. neednt tell c. mustnt have told d. mustnt tell 18. He _unwisely, but he was at least trying to do something helpful.a. may have acted b. must have acted c. should act d. would act 19. The meetings been canceled. Ann _ all that work.a.

30、 need to do b. need have c. neednt have done d. needed not to do20. “She must be in the dormitory now.” “No, she _ be there. I saw her in the classroom a minute ago.”a. mustnt b. cant c. couldnt d. wouldnt 21. He _ the 8:20 bus because he didnt leave home till 8:25.a. couldnt have caught b. ought to

31、 have caught c. shouldnt have caught d. must not have caught 22. “The door was open.” “It openI had locked it myself and the key was in my pocket.”A. cant be B. mustnt beC. cant have beenD. mustnt have been23. Since the weather is fine we walk for a whileA. mayB. mustC. might as wellD. will24. If yo

32、ur carany attention during the first 12 months，take it to an authorized dealer.A. shall needB. should needC. would needD. will need25. As it turned out to be a small house party, we _so formally.a. need not have dressed up b. must not have dressed upc. did not need to dress up d. must not dress up 2

33、6. Which of the following sentence express WILLINGNESS? A. By now she will be eating dinner. B. I shall never do that again. C. You shall get a promotion. D. My brother will help you with the luggage. 27. Which of the following best explains the meaning of “Shall we buy the tickets first”? A. He sai

34、d that we were going to buy the tickets first. B. He requested that we buy the tickets first. C. He suggested that we buy the tickets first. D. He advised us to buy the tickets first.28. Which of the following sentences expresses “probability”? A. You must leave immediately. B. You must be feeling r

35、ather tired. C. You must be here by eight oclock. D. You must complete the reading assignment on time. 29. Someone is knocking at the door. _ it be Venis？ No, it _ be her；she left for New York this morning.A. Can; mustnt B. Might; cant C. May; doesnt D. Can; cant30. Is there a movie on in the cinema

36、 tonight？ There_ be. I will phone the cinema and find it out.A. might B. should C. can D. could31. He didnt agree with me at first, but I _ persuade him to sign the agreement later. A. could B. might C. should D. was able to32. You _ out last night. I called you several times, but nobody answered. A

37、. must have been B. must be C. might have been D. could be33. Oh, Jane, youve broken another glass. You ought _ when you washed it. A. be careful B. to care C. have cared D. to have been careful34. We _ booked. Look, this restaurant is almost empty.A. must have B. cant have C. should have D. neednt

38、have35. Do you still remember the day when we went to the Great Wall？ I can t remember it well, but _ sometime last autumn？A. might it be B. could it have been C. could it be D. must it have been36. I cant get through to the general managers office anyhow.The line is busy. Someone_ the telephone.A.

39、must use B. uses C. must have been using D. must be using37. It is rather cold here. Shall we light a fire？No, we _ because things are easy to catch fire. A. wont B. cant C. mustnt D. neednt38. Listen! The fire engine is roaring. There _ be a fire somewhere. A. should B. must C. will D. ought to 39. “The interest _ be divided into five parts, according to the agreement made by both sides,” declared the judge. A. may B. sho