情态动词 modal verbs
情态动词的基本用法特点 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
表示能力: can, could, be able to
*be able to 能用于各种时态。 can / could 只能表示现在或过去的能力。
*was / were able to : “设法做成某事”
相当于 managed to do sth.
succeeded in doing sth.。
1. A computer ______ think for itself; it A must be told what to do. A. can’t B. couldn’t C. may not D. might not 2. The fire spread through the hotel very quickly but everyone ______ get out. D A. had to B. would C. could D. was able to D 3. They will ______ run this machine on their own in three months. A. can B. could C. may D. be able to
表示许可: may / might, can / could * might, could 比较委婉, 一般多用于疑问句. * can, may 表达的语言比较随便. * 在以could, might 表示征询对方意见 或表示请求时，回答应相应使用can, may.
5. — Could I borrow your dictionary?
C — Yes, of course you _______. A. might B. will C. can D. should 6. — Might I watch TV after supper? — Yes, you ________. A A. may B. must C. might D. can
2. 表示否定的情态动词的用法: mustn’t needn’t 不准, 禁止 没必要 ( = don’t have to )
shouldn’t 不应该 ( = ought not to )
won’t/ wouldn’t 不愿意
疑问句式 肯定句式 否定答式
Can/Could you do Yes, No, I we I/we/can/could sth. can’t/ couldn’t May I do sth.? Yes ,you may.
No ,you mustn’t/may not.
Must I /we do sth.?
Yes, you must No you needn’t/don’t have to. Need I do sth.? Yes ,you must. No, you needn’t/don’t have to.
C 7. You ______ return the book now. You can keep it till next week if you like. A. can’t B. mustn’t C. needn’t D. may not B 8. Johnny, you ______ play with the knife, you ______ hurt yourself. A. won’t ; can’t C. shouldn’t ; must B. mustn’t ; may D. can’t ; shouldn’t
9. --Will you stay for lunch?
--Sorry, _____. My brother is coming to see me. B
A. I mustn’t
C. I needn’t
B. I can’t
D. I won’t
10. --May I pick a flower in the garden?
C -- ________.
A. No, you needn’t B. Not, please. C. No, you mustn’t D. No, you won’t
表示推测——情态动词的重要用法. 情态动词 肯定的推测 对将来 对现在 对过去
+ V. ust/should 常见must be 可能的推测 + V.
+ V. + have done + be doing
+ V. + have done + be doing 可以用not表示“可能不” + V. + be doing + V. + be doing + have done
+ have done
1. You must be Mr Smith----I was told to expect you here. 2. He must have known what we wanted. 3. We may have read the same report. 4. He can’t have slept through all that noise. 5. There’s someone outside----who can it be? 6. What can they be doing? 7. These pills might help to cure your disease. 8. You could be right, I suppose.
may 1. I don't know where she is, she _______ be in Wuhan. 2. At this moment, our teacher ___________________ our exam papers. must be marking 这时，我们老师想必在批改试卷。 3. The road is wet. It ____________________ must have rained last night. (rain) must have been looking 4. Your mother __________________________ for you. 你妈妈一定一直在找你。
5. Philip may (might) have beenseriously in ________________________ hurt
the car accident. 菲利普可能在车祸中受了重伤. 6. ---Linda has gone to work, but her bicycle is still here.
may (might) have gone ---She _____________________ (go) by bus.
7. Mike ___________________ his car, for he came can’t have found to work by bus this morning. 迈克一定还没有找回他的车，因为早上他是坐 公共汽车来上班的。
情态动词+完成式： 1. must have done 2. may/might have done 3. can’t couldn’t jave done 4. should /ought to have done 5. shouln’t/oughtn’t to have done 6. could have done 7. needn’t have done 8. would rather have done
must 1. The ground is rather wet, so it _______ have rained last night, didn’t it? 2. Tom may have gone to Shanghai, but ____ I’m still not sure about it. 3. The ground is very dry, so it can’t have _____ rained last night. 4. Someone must have broken into our could bedroom. Who ________ have done it? 5. I really regretted wasting the hours when I should have studied hard, but it ______ was too late.
6.Your home is not far from your school, needn’t so you _________ have left in such a hurry then. would rather 7. I _____________ have come to help you with your English, but I was too busy at that time. ?8. ---I paid a visit to New York last month and we stayed at a nice hotel. could ?---Oh,you _______have stayed with Barbara.She is always willing to do you a favour.
表示“威胁”、 与第一、三人称 “警告”、“允 连用，表示征询 诺”的语气 对方的意见 Will/would 1）表示“习惯” 与第二人称连用， 2）表示“愿意/ 表示征询对方的 意见 望” 3）表示“必然性” ?1. If you ________follow my advice, I _____ will shall you some help. offer 比较内容 shall 肯定句 疑问句
?2. ______ you meet him right now or ____ shall Will he wait outside, sir?
11. He shall be punished if he disobeys. ______
如果他不服从, 就要受到惩罚. will 12. We are not going to quarrel at all if you ____ only let me speak.
只要你让我说话, 我们根本就不会吵架. B 13. --Sir, ____ he go or stay?
--Let him go. A. will B. shall C. might D. could
14. The door _______ open. won’t
这门经常打不开. D 15. Ronald ______ stay in his small garden for a long time every day in the past. A. could B. might C. should D. would 16. You _____ have the book after I read it. shall 我看完以后一定把这本书给你.
would 和 used to的比较
1、would 主要表示过去一段时间内的某种 习惯，常与表示过去的时间状语连用，意为 “总要，总是” used to 主要表示过去存在但是现在已 不再存在的习惯，意为“过去常常”。 would On Sundays he _______ go to call on the old man when he was young. used to I _______ get up late, but now I have got used to getting up very early. used to Xiao Li ________ be a model worker. He is now a university student.
可兼做行为动词的情态动词：need 、 dare 情态动词 (+动词原形) 行为动词
1.无人称和数的变化; 多用于肯定句; need 2.尤其用于： (sb.) need to do *否定句及疑问句中; dare to do *在if/whether之后; . (sth.) need to be *或与hardly, never, no one, nobody连用; done dare 3.常以needn’t 和daren’t (sth.) need doing 的形式出现; 4.dare有其过去时dared.
I daren’t ask her for a rise. 我不敢请求她加薪. How did you dare to tell her that? I wonder whether he dare stand up in public. I don’t know how she dares to wear that dress. Do you need any help? I wonder whether he need send it immediately. I need hardly tell you that the work is dangerous. The garden doesn’t need watering at the moment. You needn’t finish that work today.
判断正误: How dare you say such a thing? How dare you to say such a thing? He daren’t to speak English before such a crowd, did he? He daren’t speak English before such a crowd, dare he?
Nobody need to be afraid of catching the disease. Nobody need be afraid of catching the disease. These dishes need be cleaned carefully. These dishes need to be cleaned carefully.
These dishes need cleaning carefully.
情态动词短语的使用: would like to do… would rather do… would rather + 从句 would prefer to do...
had better do...
改错: 1. Would you like having some tea? Would you like to have some tea?
2. I’d prefer going to the lecture this evening. I’d prefer to go to ...
3. I’d rather you to go to the meeting. … you went to ... 4. He would rather to die than to give in. He would rather die than give in. 5. You’d better to have your hair cut today. You’d better have ...
1. Peter _______ come with us tonight, but he isn’t very sure B yet. (N 1993)
must 加动词原形表示“必须做”；may 加动词原形表示“可能会做”； can 加动词原形表示“能够做”；can 表示“可能性”时只用在问句和 否定句中。该句的关键在于“but he isn’t sure yet”。
B 2. Michael _______ be a policeman, for he is much too short. (1994上海) A. needn’t B. can’t C. should D. may
needn’t 表示“不必”；can’t 表示“肯定不”；后两个选项与句意差 别太大。此句的关键在于 “for he is much too short”.
C 3. It’s nearly 7:00. Jack ____ be here at any moment. (N 1995)
must + be 表示“肯定会”；need + be 表示 “需要在”； should + 动词原形表示“非常有可能”；can 表示可能性 只用在否定和疑问句中。 B 4. Johnny, you _______ play with the knife, you _______ hurt yourself. (N 1996)
A. won’t, can’t C. shouldn’t, must
B. mustn’t, may D. can’t, should
前句表示“你不能玩刀”，此处的 “不能”并非表示“能 力”，而是表示“允许”，所以只能用“mustn’t”；后句 表示“可能会伤着你自己”，故用 may。
5. ---- Are you coming to Jeff’s party? D ---- I’m not sure. I _____ go to the concert instead. ( N 2000) A. must B. would C. should D. might
此句的关键在于“I’m not sure”，既然不能肯定，只能是 一种“可能性”。 A 6. Mr. Bush is on time for everything. How _____ it be that he was late for the opening ceremony? (2001上海春季) A. can B. should C. may D. must 此句的意思为：“Bush 先生总是很守时，他怎么可能在 出席开幕仪式时迟到呢？“ can 在否定句或疑问句中表示 “可能性”。
7. --- Is John coming by train? D --- He should, but he ______ not. He likes driving his car. (N 2002) A. must B. can C. need D. may
此句的关键是“He likes driving his car.” can 和 may 都可 用于否定句中，can’t 表示“根本不可能”，语气很强； may not 表示“也许不可能”，语气较弱。 8. --- I heard they went skiing in the mountains last winter. C --- It _________ true because there was little snow there. (N 2002北京) A. may not be C. couldn’t be B. won’t be D. mustn’t be
couldn’t 的语气比 can’t 弱。
A 1. Tom ought not to _______ me your secret, but he meant no harm. (N1993) A. have told B. tell C. be telling D. having told
ought to 相当于 should；此句的关键是“He meant no harm”，显然指的是过去的事。 C 2. I told Sally how to get here, but perhaps I _______ for her. (N 1994) A. had to write it out B. must have written it out C. should have written it out D. ought to write it out should have written 意指“本该写但实际上并没有写”。
3. --- There were already 5 people in the car but they managed to take me as well. D --- It ________ a comfortable journey. (N 1995) A. can’t be B. shouldn’t be C. mustn’t have been D. couldn’t have been 此句谈论的是过去的经历，故 A、B 不合题意；must 表示
判断和推测只能用在肯定句中。 C 4. Susan_______ written a report like this. (1995上海) A. can have C. can’t have B. mustn’t have D. ought to not have
该句的意思为 Susan 不可能写出这样的报告来。ought to have done 的否定式为 ought not to have done。
C 5. Jack ____ yet, otherwise he would have phoned me. (N 97) A. mustn’t have arrived C. can’t have arrived B. shouldn’t have arrived D. needn’t have arrived
此句的关键是后半句，“otherwise he would have phoned
他会打电话给我的”，由此可见，他肯定没到。 6. --- I stayed at a hotel while in New York. A --- Oh, did you? You______ with Barbara. (N 1998) A. could have stayed B. could stay
C. would stay
D. must have stayed
D 7. There was a lot of fun at yesterday’s party. You ____ come, but why didn’t you? (1999上海) A. must have B. should C. need have D. ought to have
B 8. I was really anxious about you. You _____ home without a word. (N 2001) A. mustn’t leave C. couldn’t have left B. shouldn’t have left D. needn’t leave
C 9. Oh, I’m not feeling well in the stomach, I _____ so much fried chicken just now. (2002上海春季) A. shouldn’t cut B. mustn’t have eaten C. shouldn’t have eaten D. mustn’t eat
4. shall; should 的特殊用法
D 1. It has been announced that candidates ____ remain in their seats until all the papers have been collected. (2002上海) A. can B. will C. may D. shall
将要、可以”来表示。而 shall 在第二、三人称里面表示
一种“命令、警告、承诺”等。 C 2. It’s nearly 7:00. Jack _____ be here at any moment. (N 95) A. must B. need C. should D. can
3. --- When can I come for the photos? I need them tomorrow afternoon. B --- They __________ be ready by 12:00. (N 1998) A. can B. should C. might D. need 此句应是店主对顾客的承诺。
C 4. You can’t imagine that a well-behaved gentleman _____ be so rude to a lady. (2001上海) A. might B. need C. should D. would should 与 how; why 等表示疑问或否定的词连用时，用来 表示一种惊奇的心情，意思为“居然、竟然”
1. --- Shall I tell John about it? A --- No, you ______. I’ve told him already. (N 1994) A. needn’t B. wouldn’t C. mustn’t D. shouldn’t
此句的关键是“I’ve told him already”，由此可见，你就不 必再对他说了。
2. --- Could I call you by the first name? C --- Yes, you__________. (1998上海) A. will B. could C. may
在回答 “Could I …”这类婉客气的请求时，只能回答 “Yes, you can 或 may”。不能用 could 或 might。
3. --- Will you stay for lunch? B --- Sorry, _____. My brother is coming to see me. (N 1999) A. I mustn’t B. I can’t C. I needn’t D. I won’t
此句的关键是 “My brother is coming to see me.” 所以我不 能在这儿吃饭。
4. ---- Write to me when you get home. C ---- __________. (2001北京春季) A. I must B. I should C. I will D. I can 在回答对方的请求或命令时，应该用 “Yes, I will.”而不 能使用 would 或 should。
D 1. I wonder how he _______ that to the teacher. (1996上海) A. dare to say B. dare saying C. not dare say D. dared say 注意比较 dare 和 need 的两种词性的不同用法。 2. The fire spread through the hotel very quickly but everyone C ______ get out. (N 1997) A. had to B. would C. was able to D. could 注意比较 could 与 was able to 的用法区别。 A 3. When he was there, he _______ go to that coffee shop at the corner after work every day. (1996上海) A. would B. should C. had better D. might would 在此处表示过去惯常的动作。
1. The fire spread through the hotel very quickly, but everyone_______get one. C A. were able to B. would C. was able to D. could 2. You____return the book now, you can keep C it until next week if you like, A. can’t B. mustn’t C. needn’t D. may not A 3. When he was there, he______ go to that coffee shop at the corner after work every day. A. would B. should C. had better D. might C 4. ---Could I use your bike?—Yes, of course.you___.
5. ----Will you stay for lunch? ----Sorry, _______. My brother is coming to see B me. A. I oughtn’t to B. I can’t C. I needn’t D. I shouldn’t B 6. ----______I invite Jcak to the party? -----Yes, it’ll be nice if you______. A. Will; may B. Shall; will C. Shall;shall D. Will; will 7. ---There were already five people in the car, but they managed to take me as well. D ---It______a comfortable journey. A. can’t be B. shouldn’t be C. mustn’t have been D. couldn’t have been
8. We______last night, but we went to the C concert instead. A. must have studied B. might study C. should have studied D. would study D 9. There was plenty of time. She_____. A. mustn’t have hurried B. couldn’t have hurried C. mustn’t hurry D. needn’t have hurried 10. Yesterday, D Jane walked away from the discussion. Otherwise. She____something she would regret later. A. had said B. said C. might say D. might have said.
11. ----Did you scold him for his mistake? ----Yes, but______it. D A. I’d rather not do B. I’d better not do C. I’d better not have done D. I’d rather have not done