情态动词讲义和专项练习.docx

1、情态动词讲义和专项练习情态动词讲义和专项练习情态动词有 can (could), may (might), must, have to, shall (should), will (would), dare (dared), need (needed),ought to 等。情态动词无人称和数的变化； 不能单独使用，必须 与其后的动词原形构成谓语一、 can, could1)表示能力(体力、知识、技能) 。e.g. Can you lift this heavy box? (体力)Mary can speak three Ianguages.(知识)Can you skate?(技能)此时可用

2、be able to代替。can只有一般现在时和一般过去式；而 be able to则有更多的时态。e.g. I II not be abIe to come this afternoon.当表示经过努力才得以做成功某事”时应用 be able to,不能用can。如：e.g. He was able to go to the party yesterday evening in spite of the heavy rain.Although he can t swim, yet he was able to cross the river.2)表示请求和允许。e.g. Can I go n

3、ow? Yes, you can. / No, you can t.此时可与may互换。在疑问句中还可用 could, might代替，不是过去式，只是语气更委婉， 不能用于肯定句和答语中。e.g. Could I come to see you tomorrow? Yes, you can. ( No, I m afraid not. )3)表示客观可能性(客观原因形成的能力) 。e.g. Theyve changed the timetable, so we can go by bus instead.This hall can hold 500 people at least.4)表示推

4、测(惊讶、怀疑、不相信的态度) ,用于疑问句、否定句和感叹句中。e.g. Can this be true?This can t be done by him.How can this be true?5)“can + have done”主要用于否定句和疑问句中，表示对过去发生的行为怀疑或不肯定。e.g. He cannot have been to that town.Can he have got the book?“ could + have done ”表示虚拟语气。e.g. But for your help, we couldn t have finished the task

5、before the deadline.You could have achieved better results but you wasted the valuable time.6) 习惯用法：cannot too 再 也不过分”e.g. You cannot be too careful in the choice of your friends. 二、 may, might1）表示请求和允许。 might比may语气更委婉，而不是过去式。否定回答时可用 can t或mustn，表示不可以，禁止”。e.g. Might/ May I smoke in this room? No, yo

6、u mustn t. May/Might I take this book out of the room? Yes, you can. (No, you can t / mustn t. )用 May I. ？征徇对方许可时比较正式和客气，而用 Can I. ？在口语中更常见。2)用于祈使句，表示祝愿。e.g. May you succeed!3)表示推测、可能性(表示此意时，不用于疑问句) 。 might 不是过去式，它所表示的可能性比 may 小。e.g. He may /might be very busy now.Your mother may /might not know the

7、 truth.4)“ may / might + have done ”表示对过去行为的推测。e.g. Without the heavy traffic, we might have caught the train.5)习惯用法： may / might as well + do “不妨”e.g. You might as well have an another try.三、 must, have to1)表示必须、必要。e.g. You must come in time.t,don thave tohave to 有更在回答引出的问句时，如果是否定的，不能用 mustn t禁止，不准

8、)，而用needn (不必) .e.g. Must we hand in our exercise books today? Yes, you must. No, you don thave to / you neednt.2) must是说话人的主观看法， 而have to则强调客观需要。 must只有一般现在时，多的时态形式。e.g. The play isn t interesting, I really must go now.I had to work when I was your age.3)表示推测、可能性(只用于肯定的陈述句)e.g. Youre Toms good frie

9、nd, so you must know what he likes best.Your mother must be waiting for you now.表示肯定推测的否定句，用 cannote.g. This cannot be your pen.4) “must + have done”对过去行为的肯定推测，否定句用 cannot.e.g. It must have been rainy yesterday, wasn t it?It must have rained yesterday, didn t it?5)have got to 是 have to 的口语形式。e.g. Yo

10、u haven t got to go to school today, have you?6)must “偏偏”e.g. Why must it rain on Sunday?We were going to see a movie, but it must rain yesterday.四、 dare, need1) dare 作情态动词用时 , 常用于疑问句、否定句和条件从句中 , 过去式形式为 dared e.g. How dare you say Im unfair?He darent speak English before such a crowd, dare he?If we

11、dared not go there that day, we couldn tget the beautiful flowers.2) need 作情态动词用时 , 常用于疑问句、否定句。 在肯定句中一般用 must, have to, ought to, should 代替。e.g. You needn t come so early. Need I finish the work today? Yes, you must. / No, you needn t.3) dare 和 need 作实义动词用时， 有人称、时态和数的变化。在肯定句中， dare 后面常接带 to 的 不定式。在疑

12、问句和否定句中， dare 后面可接带 to 或不带 to 的不定式。而 need 后面只能接带 to 的不定式。e.g. I dare to swim across this river.He doesn t dare (to) answer.He needs to finish his homework today.4)“needn t + have done表示虚拟语气，本不必做某事而事实上却做了。e.g. You needn t have waited for me.5)need doing = need to be done.e.g. The washing machine need

13、s repairing. = The washing machine needs to be repaired.6) I dare say”意为我猜测”e.g. I dare say he will come.五、 shall, should, ought to1)shall 用于第一人称，征求对方的意见。e.g. What shall we do this evening?2)shall 用于第二、三人称，表示说话人给对方的命令、警告、允诺或威胁。e.g. You shall fail if you don HWo)k hard.(He shall have the book when I

14、finish it.( 允诺 )He shall be punished.(威胁)3)shall 用于第一，第三人称疑问句中，表示说话人征求对方的意见或向对方请示。e.g. Shall we begin our lesson?When shall we be able to leave the hospital?4)should, ought to 表示“应该” ， ought to 表示义务或责任，比 should 语气重。e.g. I should help her because she is in trouble.You ought to take care of the baby.5

15、)表示劝告、建议和命令。 should, ought to 可通用，但在疑问句中常用 should。e.g. You should / ought to go to class right away.Should I open the window?6)should 表示主观推测， “估计”“按道理应该”e.g. He ought to/should be home by now.They should finish it by now.7)“ should + have done”用于虚拟语气，本应该做某事而实际上并未做某事。e.g. You should have arrived here

16、 5 minutes earlier.8)特殊用法：“竟然”“居然”表示说话人感到意外，赞叹，愤怒，惊异等感情。e.g. You can t imagine the gentleman should be a thief.e.g. I dont know why you should think I did it. “倒是”，用于第一人称时表示说话人的一种谦逊，客气，委婉的语气。e.g. I should think it would be better to try it again.I should advise you not to do that.六、 will, would1) wi

17、ll 表示请求、建议等， would 更委婉。e.g. Will / Would you pass me the ball, please?2) will 表示意志、愿望和决心。e.g. I will never do that again.They asked him if he would go abroad.3) would 表示过去反复发生的动作或某种倾向。 would 表示过去习惯时比 used to 正式， 且没有“现已无此习惯”的含义。e.g. During the vacation, he would visit me every other day.The wound wou

18、ld not heal.4)would 表示估计和猜想。e.g. It would be about ten o clock when she left home.5)would 用在虚拟语气中(参考虚拟语气语法) 。e.g. If it should rain, the crop would be saved.七、 情态动词 + 不定式完成式( have done)1) can / could + have done 在肯定句中表示“本来可以做而实际上未能做某事” ，是虚拟语气；在疑问句或否定句中表示对过去行为的怀疑或不肯定 , 表示推测。e.g. You could have done b

19、etter, but you didn ttry your best. (虚拟语气)He cant have been to that town. (推测)Can he have got the book? (推测)2) may / might + 不定式完成式( have done) 表示对过去行为的推测。不能用于疑问句中。 might 所表示的可能性比 may 小。e.g. He may not have finished the work.If we had taken the other road, we might have arrived earlier.3) must +不定式完

20、成式( have done) 用于肯定句中，表示对过去行为的推测。意为“一定、想必” 。其疑问、否定形式用 can， cant。 can / could + have done 表示推测。e.g. You must have seen the film Titanic .He must have been to Shanghai.4) should +不定式完成式( have done) 用于肯定句中，表示对过去行为的推测。e.g. He should have finished the work by now 。表示“本应该做而实际上没有做某事” ，其否定式表示某种行为本不该发生却发生了。

21、可以与 ought to +不定式完成式(have done)互换。e.g. You ought to / should have helped him. (but you didn t.)She shouldnt have taken away my measuring tape, for I wanted to use it. 5) neednt + 不定式完成式( have done) 表示“本来不必做而实际上做了某事” 。e.g. You needn t have watered the flowers, for it is going to rain. 6) will + 不定式完成

22、式( have done)主要用于第二、三人称，表示对已完成的动作或事态的推测。 e.g. He will have arrived by now.情态动词专项练习1.He you more help, even though he was very busy.A. might have give n B. might give C. may have give n D. may give2.Jenny have kept her word. I won der why she cha nged her mind.A. must B. should C. n eed D. would3. -C

23、ould I borrow your dict ion ary? -Yes, of course you A. might B. will C. can D. should4.I told Sally how to get here, but perhaps I for her.A. had to write it out B. must have writte n it outC. should have writte n it out D. ought to write it out5. Shall I tell Joh n about it?No, you . Ive told him

24、already.A. need nt B. would nt C. must nt D. should nt6. There were already five people in the car but they man aged to take me as well. It a comfortable journ ey.A. cant be B. should nt be C. must nt have bee n D. could nt have bee n7.Its n early seve n oclock. Jack be here at any mome nt.A. must B

25、. n eed C. should D. can8.Whe n he was there, he go to that coffee shop at the corner after workevery day.A. would B. should C. had better D. might9.Sir, you be sitt ing in this wait ing room. It is for wome n and childre n only.A. ought nt to B. cant C. wo nt D. need nt10.The fire spread through th

26、e hotel very quickly but every one get out.A. had to B. would C. could D. was able to11.-Whe n can I come for the photos? I n eed them tomorrow afternoon.-They be ready by 12:00.A. can B. should C. might D. n eed12.-I stayed at a hotel while in New York.-Oh, did you? You with Barbara.A. could have s

27、tayed B. could stay C. would stay D. must have stayed13. Will you stay for lunch?Sorry, ,My brother is coming to see me.A. I must nt B.l cant C. I need nt D.I wo nt14.Sorry rm late. I have turned off the alarm clock and gone back to sleep aga in.A. might B. should C. can D. will15.I should have bee

28、n there, but I not find the time.A. would B. could C. might D. should16.My sister met him at the Grand Theatre yesterday afternoon, so he your lecture.A. could nt have atte nded B. n eed nt have atte ndedC. must nt have atte nded D. should nt have atte nded17.- Are you coming to Jeffs party?-Im not

29、sure. I go to the concert in stead.A . must B . would C. should D. might18.Mr. Bush is on time for everyth ing. How it be that he was late for the ope ning ceremony?A . can B. should C . may D . must19 He hesitated for a mome nt before kick ing the ball, otherwise he a goal.A . had scored B . scored

30、 C . would score D . would have scored20. Write to me whe n you get home.A . I must B . I should C . I will D . I can21.1was really an xious about you. You home without a word.A. must nt leave B. Should nt have left C. Could nt have left D. need nt leave22.Oh, I m not feeling well in the stomach, I

31、so much fried chicken just now.A. should n cut B. must n thave eate n C. should n have eate n D. must n teat23.-I heard they went skii ng in the mountains last win ter.-It be true because there was little snow there.A may not be B won t be C couldn t be D mustn t be24.It has bee n announced that candidates rema in in their seats un til all the papers have bee n collected.A can B will C may D shall25.A left-luggage office is a place