Presentation on theme: "Modal Verbs. can & could Man cannot live without air. ---- 能力 SARS can be very dangerous. ---- 可能性 You can have the book when I have finished it. ----"— Presentation transcript:
can & could Man cannot live without air. ---- 能力 SARS can be very dangerous. ---- 可能性 You can have the book when I have finished it. ---- 许可 Can: 本能 be able to: 经过努力学习才能够
The fire spread through the hotel very quickly, but everyone ______ get out. A. had to B. would C. could D. was able to 当我们要表示 ” 某件事情已经成功完成 ” 时, 应用 was/were able to = manage to do /succeeded in doing, 不用 could He was able to go to the party yesterday. can (can / could) be able to (is/ are/ was/ were / have been/ had been /will be able to) D
may & might 用于祈使句表祝愿 May you both be very happy! May you succeed! 1. “_____I stop here, sir?” “ No. Go on to the next paragraph, please.” A. Will B. May C. Would D. Ought B
2.--Is John coming by train? --He should, but he ____ not. He likes driving his car. A. must B. can C. need D. may --Can it be true? --Yes, it must be.( 肯定 ) --it may be( 可能 )/might( 可能性更小 ) --No, it can’t be true.( 绝对否定 ) --No, it mayn’t be true.( 可能 ) D
must & have to 1.mustn’t 表示不准, 禁止 You mustn’t walk on grass. You mustn’t pick the flowers in the park. 2.Must 引导的问句 --Must we hand in our homework today? --Yes, you must. --No, you needn’t./No, you don’t have to. Need? Need I go now?
3.Must 表示 “ 一定 ”, “ 必定 ” 等推测意义时, 只用 在肯定句中. 否定句疑问句用 “can” It must be true. It can’t be true. Can it be true? Must have done 对已经发生事情的肯定猜测 Must be/V 原形 对一般事实的肯定猜测 Must be doing 对正在进行事件的肯定猜测
(6)They must have passed the exam, They must have passed the exam yesterday, 昨天夜里一定下过雨了. It must have rained last night. (7)You must be a doctor. 他肯定有很多书. He must have a lot of books. 她肯定知道露西的地址. She must know Lucy’s address. haven’t they? didn’t they?
(8)He must be watching TV. 他不在这里, 他肯定在家里睡觉. He isn’t here. He must be sleeping at home. 否定形式 They must have passed the exam yesterday. They can’t have passed the exam yesterday. You must be a doctor. You can’t be a doctor. He must be watching TV. He can’t be watching TV.
1. Johnny, you ____ play with knife, you ____ hurt yourself. A. won’t ； can’t B. mustn’t ； may C. shouldn’t ； must D. can’t ； shouldn't 2. He ______see a doctor before it is too late. A. must B. must have to C. can D. need 3. Our teachers are at work. You ____ make so much noise. A. won’t B. mustn’t C. may not D. needn’t B A B
4.—Must I write down the new words now? —No, you _____. A. needn’t B. mayn’t C. mustn’t D. can’t —Need I start from the beginning? — No, you needn’t. Yes, you must. 5.--Look, it ___ be Lao Wang. --No, it ___ be him. He has gone abroad. A. may ； must B. must ； mayn’t C. must ； can’t D. can ； mayn’t A C
6.I can’t find Dr Lopez anywhere in the office building. Where ____ he have gone? A. must B. can C. should D. need 7.— Isn’t that Ann’s husband over there? — No, it ____be him-- I’m sure he doesn’t wear glasses. A. can’t B. must not C. won’t D. may not can’t 表不可能，语气肯定，破折号加以注 释，据题意，选 A 。 B
shall & should 1.The boss said to the secretary, “If you work well, you ______have a rise.” A. must B. shall C. ought D. would B ( 允诺 ) 2.--The room is so dirty. ____we clean it ? --Of course. A. Will B. Shall C. Do D. Would B( 征询意见 )
情态动词 + 不定式完成式 1.must have done 对过去行为的推测, “ 一定, 想必 ” You must have seen the film ET.( 疑问, 否定用 can) 2.may/might have done 推测过去可能发生的事 He may/might have told the secret to her. He may /might have finished the exercise, but he didn’t hand in.
3.should/ought to have done 本该做而实际上 没做 1)You should/ought to have turned off the electricity before you left. 2)You should/ought to have helped him. ( but you didn’t ) oughtn’t to/shouldn’t have done 本不该做 3)You oughtn’t to/shouldn’t have told the secret to her. 4.needn’t have done 本不必做而事实上做了 You needn’t have watered the flowers, for it is going to rain.
5.could have done 过去可以做而实际上未能做 1)You could have done better, but you didn’t try your best. 2)We could have finished the task, but it was always raining. 6.can’t/couldn’t have done 过去不可能发生的事 情 ( 和 must 相对 ) 1) He can’t (couldn’t )have stolen your money. 2)Can he have got the book? 3)Where could Mary have gone?
1. He looks sleepy. He must __________ bed very late last night. (go; have gone) 2. I ought ___________ those books to the library last week. (to have taken; to take) 3. The mother is telling her son, “You __________ eat with your fingers!” (wouldn’t; mustn’t). have gone to have taken mustn't
4.She ____ to the cinema, for I saw her just now. A. mustn’t have gone B. may not go C. can’t have gone D. needn’t go 5.You ____ her at the beginning, but now it is too late. A. ought to have refused B. ought to refused C. may refuse D. needn’t refuse C A