情态动词的用法
一、情态动词的概念及分类：
情态动词表示说话人对某一动作或状态的态度，其语言环境显得很重要。所谓情态动词是指含有一定的含意，可以表达某种感情和说话的口气，但是它不可以单独使用作谓语动词。学习情态动词主要学习英语国家的语言习惯和表达法，特别是在口语中不要过分追求原理，更不要不根据说话场合而进行推理，编造出一些语法结构正确的中文式英语。在特定的语言环境中对情态动词的基本用法的运用能力是近几年高考英语试题测试的目标之一。
情态动词的类型有：
1、 词型没有变化的有：should，shall，must；
2、 词型有变化的有：can（could），may（might），will（would）；
3、 三个带to的是：ought to，used to，have to；be able to
4、 need，dare有双重词性（行为动词和情态动词）；
5、 be able to， have to有人称时态变化；
6、had better，would rather为不规则情态动词。
二、情态动词的特征
1、属于虚词，有一定的词义，但不能单独作谓语，他们要和行为动词或连系动词连用，一起构成谓语。例如：He can speak both English and French.
2、适用于主语的各种人称和数（have to 例外，主语是第三人称单数时，要用has to）。
We must work hard at our lessons./Tom has no bike, so he has to walk home every day.
3、后接动词原形，即不带to的不定式，（ought to, have to, used to，be able to本身带有to）。例如：
He may lose his way./You ought to obey the school rules.
4、具有助动词的作用，即可用来构成否定句、疑问句及用于简明答语。例如：
--I can’t swim. Can you swim？--No, I can’t, either.
三、情态动词的句式：
1、肯定式：主语+情态动词+动词原型。
2、否定式：主语+情态动词+not+动词原型。
3、疑问式：情态动词+主语+动词原型+？
四、情态动词的八大考点
1、can/may/must/need问句的回答方式：
疑问句式 肯定答式 否定答式
Can/Could you do …？ Yes， I/we can/could. No， we can’t/couldn’t.
May I do ...? Yes, you may. No, you mustn’t/may not.
Must I/we do ….? Yes, you must. No, you needn’t/don’t have to .t/don’t have to.
Need I do …? Yes, you must. No, you needn’t/don’t have to.
2、can ,could, may, might , must表示判断的用法比较
1).must用于肯定判断,后跟动词原型则表示对于现在情况的肯定判断;后跟”have + pp”表示对于过去情况的肯定判断.must +be +doing表示”想必正在做某事”的意思。例如:
It is so wet on the ground, so it must have rained heavily last night, didn’t it?
The light is on in the office now, so there must be someone in it, isn’t there?
--Where is Mr. Li now？--He must be working in his class，I think.
2).may/might后跟动词原型表示对于现在情况的可能性推断;后跟“have + pp”表示对于过去情况的可能性推断。例如:
I’m not sure whether he will come today. He may/might be ill today.
3)can/could用于否定句或疑问句,后跟动词原型表示对于现在或当时情况的否定或疑问性推测;后跟“have + pp”表示对于过去情况的否定或疑问性推测。例如：
Tom has gone to Beijing, so you can’t see him in our school now.
Who could have worked ut(work out) the difficult problem in such terrible condition then?
3、情态动词的完成式是每年必考的热点,表示“推测”、“责备”、“怀疑”等多种意义。
1） must + have + pp：表示对于过去情况的肯定判断。
2） may/might + have + pp：表示对于过去情况的可能性推断。
3） can’t + have + pp：表示对于过去情况的否定或疑问性推测。
4） needn’t + have +pp表示过去不必做却已经做了的事情。包含说话人“责备”的语气
例如：We had plenty of time left then , so you needn’t have handed in your test paper so early.
5)should/ought to +have +pp表示过去该做而没有做的事情。例如:
How I regret the time I wasted! I should have studied harder then.(=In fact, I didn’t.)
6）should not have done/ought not to have done sth-表示过去不该做却已经做了的事情。
I’m very sorry that I should not have said such rude words to you at that time!
7）过去原本能做到却没能做到的事情：could +have +pp .例如：
He could have passed the driving test if he had been so careless.
8）本来想做却未做成的事：would rather have done。例如：
I would rather have come to help you with your English， but I was too busy.
4、shall & will 的比较:
比较内容 肯定句 疑问句
Shall 表示“威胁”、“警告”、“允若” 的语气或说话人坚定的决心。 与第一、三人称连用，表示征询对方的意见。
Will/Would 1）表示“习惯“，2）表示“愿意/望”；3）表示“必然性” 与第二人称连用，表示征询对方的意见
例如：If you will follow my advice, I shall offer you some help.
Will you meet him right now or shall he wait outside, sir?
5、need和dare作行为动词或情态动词比较:
比较内容 是否有人称和数的变化 是否借助与助动词 搭配
行为动词 有 是 +to do sth / sth.
情态动词（否/疑） 没有 否 do sth.
Tom needn’t have left so hurry, for he had a lot of time left then.=Tom didn’t need to leave so hurry, for he had a lot of time left then.
6、can与be able to的比较，以及must 与have to的比较:
1)can除了表示能力外，还可以表示否定或疑问的可能性，没有人称与数的变化；而be able to除能表示能力外，还可以表示具备了某种能力所导致的结果，有人称与数的变化,能与助动词连用。例如
（1）Few people could /were able to send their children to school before liberation。
（2）--Could Tom be in the office now？--No， he can’t, for he is ill in hospital.
(3).Tom was an excellent swimmer, so he was able to swim back to the bank when the ship sank.
2)must表示“主观”的必须，没有人称与数的变化，不能与其他情态动词或助动词连用；have to系半情态动词，表示“客观”的必须或“不得不”的意义，能与助动词连用。（4）It rained heavily last night，so we had to take a taxi to visit the museum。
(5)Every student must obey the school rules and become a good student in everything。
7、used to和would的比较：
两者都可表示“过去惯常”， 其区别在于：
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“过去经常”。
(6)On Sundays he would go to call on the old man when he was young.
(7)I used to get up early, but now I have got used to getting up very early.
2) 还可以与状态的动词连用，表示过去的状态，而 没有这种用法。下面两句只可用used to ，而不可用would.
(8)My little sister used to like the picture-books.
(9)Xiao Li used to be a model worker. He is now a university student.
8、情态动词的否定式比较：
mustn’t:禁止，不准；can’t/couldn’t:不能，不可能；may not:不可以、可能不；needn’t:不必；shouldn’t:不该；won’t/wouldn’t不愿意;daren’t:不敢。
配套情态动词练习：
1.The fire spread through the hotel very quickly， but everyone ____ get out.(NMET97)
A. were able to B. would C. was able to D. could
2.You _______ return the book now, you can keep it until next week if you like.
A. can’t B. mustn’t C. needn’t D. may not
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
4..---When can I come for the photos?Ｉneed them tomorrow afternoon.
---They ________ be ready by 12:00.(NMET 1998)
A. can B. should C. might D. need
5---Could I use your bike? ---Yes, of course, you________.
A. might B. will C. can D. should
6.-Which would you rather have, tea or coffee?--____________.(1996年上海市高考题)
A. Sure, I would B. Yes, please. C. Yes, both. D. Neither, thank you.
7.-Will you stay for lunch?-Sorry, ________. My brother is coming to see me.(NMET 1999)
A.I mustn’t B.I can’t C.I needn’t D. shouldn’t
8. --________ I invite Jack to the party
---Yes, it’ll be nice if you __________.
A. Will; may B. Shall; will C. Shall ; shall D. Will ;will
9..---I stayed at a hotel while in New York.
---Oh, did you? You __________ with Barbara.(NMET1998)
A. could have stayed B. could stay C. would stay D. must have stayed
10. ---There were already five people in the car, but they managed to take me as well.
---It__________ a comfortable journey. (NMET1995)
A. can’t be B. shouldn’t be C. mustn’t have been D. couldn’t have been
11.You say you will not do it, but I say you _________ do it.
A. would B. will C. shall D. need
12. He _______ you some help, even though he was very busy.
A. might give B. might have given C. would have given D. needn’t have given
13.---Did James come---I don’t know. He _________ while I was out.
A. had come B. must have come C. might have come D. should have come
14. ---Alice, you feed the bird today,_______?--–But I fed it yesterday.(NMET 1999)
A. do you B. will you C. didn’t you D. don’t have to
15. John, you ___________play with your knife, you ______ hurt yourself! (NMET1995)
A. won’t; can’t B. mustn’t; may C. shouldn’t; must D. can’t; shouldn’t
16.I ___________ pay Tracy a visit, but I’m not sure whether I will have time.（2004浙江）
A. should B. might C. would D. could
17. The little girl ________ dance before so many guests, _________________?
A. doesn’t dare to; dare B. dare not; does C. dares not; dare D. daren’t ; dare
18. ____________ you succeed in the contest tomorrow.
A. Will B. Must C. May D. Shall
19. I wish all of you to have a good time here, ____________ I?
A. will B. shall C. need D. may
20. It must have rained heavily last night, ____________it ?
A. mustn’t B. needn’t C. hasn’t it D. didn’t
21．I often see lights in that empty house. Do you think I _________ report it to the police?(2004全国,21)
A. should B. may C. will D. can
22.-Isn’t that Ann’s husband over there? –No, it _________ be him. I’m sure he doesn’t wear glasses.(2004全国,29)
A. can’t B. must not C. won’t D. may not
23.-Are you going to Jeff’s party? –I’m not sure. I ________ go to the concert instead.(2000全国;15)
A. must B. would C. should D. might
情态动词的用法配套练习参考答案
1-5:CCABC 6-10:DBBAD 11-15:CBCBB 16-20:ADCDD 21-23:AAD
责任编辑：李芳芳