语法课情态动词.docx

1、语法课情态动词情态动词1. can / coulda. 表示能力He can speak a little Japanese in addition to English. Man cannot live without airCan you finish this work tonight?b. 表示许可 You can(not) have the book. Can I use your phone? could也可表示请求，语气更委婉，主要用于疑问句，不可用于肯定句，答语应用can(即：could不能 用于现在时态的简略答语中)，如：-Could l come to see you to

2、morrow morning7-Yes，you can.(否定答语可用No，Im afraid not)Could you please ? Could I use your dictionary? - Yes, you can.c. 有时候会 He is a bad-tempered fellow, but sometimes he can be charming. They can be very valuable. d. 在否定句和疑问句中表示猜测(cant不可能)Someone is knocking. Who can it be?It cant be Mr. Li. Because

3、he is away on business.不可能，肯定不It cant have rained last night, for it is dry outside. e. 与possibly 连用; 用于asas one canCan/could sb. possiblyCan he possibly come?What on earth can she possibly mean?I will come back as soon as I can. Sb. cant/couldnt possibly某人不可能I cant possibly allow you to go home in

4、this weather.f. 表示惊异，怀疑不相信的态度(主要用在否定句、疑问句或惊叹句中)如：Can this be true?How can you be so rude!This cannot be done by Mary. How can you be so rude!注意：can 与be able to 区别：can表能力，只用一般过去时和一般现在时be able to表能力+成功，即最终设法做成了某事。有各种时态,可以与别的情态动词连用。The fire spread through the hotel very quickly, but everyone _ get out.

5、（NMET97）A. was able to B. could C. had to D. would g. 固定句型can not too /can never too 再也不过分You can never be too careful. We can never attach too much importance to balanced diet. 2. may / mighta. 表示允许, might 语气更委婉在表示请求、允许时，might比may的语气更委婉一些，否定回答时要用mustnt，表示不 可以、禁止、阻止之意如：You may drive the car-Might l

6、use your pen?-No，you mustnt .用May I征询对方许可在文体上比较正式，在口气上比较客气。在日常口语中，用Can I征询对方意见更为常见。May I use your ruler?- Yes, help yourself. / Yes, you may. - No, you mustnt. b. 表示可能性, might 语气更弱He may feel bored. He may have read it before.c. 用于祈使句中表示祝愿。如：May you succeed! May God bless you!d. 用于目的和让步状语从句中，表强调I ma

7、y be slow, but at least I dont make mistakes. Write to him at once, so that he may know it in time. e. 固定搭配：may/might as well 不妨，还不如Theres no bus. We may as well go home on foot now. may well 很有可能What you say may well be true. f. 用于虚拟语气中Had they known what was coming next, they _ second thoughts.(20

8、12浙江高考19)A. may have B. could haveC. must have had D. would have had3. will/ would a. 表示将来时He said he would wait for me. b. 表示请求或建议, would 语气更委婉Will / would you type this, please?Would you pass me the book?c. 表示意愿I will pay you the money you ask. My car wont start. d. 表示习惯，will 表示现在的习惯，would表示过去的习惯，

9、区别：used to现已无此习惯 A drowning man will catch at a straw(稻草) . He would sit there for hours, doing nothing. The wound would not heal(愈合) During the vacation he would visit me every week In winter morning she would sit at the gate waiting for his son.e. 表示决心I will never do that againf. 用will be和will+hav

10、e+过去分词的结构表示推测，主要用于第二、三人称。前者表示对目前情况的推测，后者表示对已经完成的动作或事态的推测。如：This will be the book you want He will have arrived by now。It would be about ten when he left home I thought he would have told you a11 about it4. shall(shant)a. 用于第一三人称的疑问句，表示说话人征求对方的意见或向对方请示。Shall I turn on the TV? Shall the boy come in?le

11、ts go for a walk, shall we? Let us go for a walk, will you?b. 用于二三人称的陈述句表示说话人给对方的命令、警告、允诺、威胁或决心等。You shall have the money as soon as I get it.He shant come here.(I wont let him come.)You shall fail if you dont work harder(警告)He shall have the book when l finish reading(允诺)He shall be punished(威胁)c.

12、用于法律、法规条文、合同等，按规定应该履行的义务等。All payment shall be made in cash，according to the agreement.Anyone who drives after drinking alcohol _ be punished according to the traffic regulations.A. can B. shall C. may D. could5. must/ have to a. 表示必须You must come to school in time回答must引出的问句时，如果是否定的回答，不能用mustnt，而要用

13、neednt或dont have to。mustnt表示禁止，不可以Must we hand in our homework?- Yes, you must. - No, you neednt./ No, you dont have to. b. 表示肯定地猜测It must have rained last night.My mother must be having breakfast.( 表示对正在进行的动作的猜测), isnt she?My sister must be at home.(对现在的状态进行猜测), isnt she?My mother must stay at home

14、 now, doesnt she?He must have gone to bed, hasnt he？It must have rained last night. ( 表示对已经发生过的事情的猜测)，didnt it?He must have been there the day before yesterday, wasnt he ?c. 硬要，一定要，非得要If you must know, I am 18. Why must it rain at the weekends?d. must 与have to 的异同have to的含义与must相似，两者往往可以互换使用，但must与h

15、ave to有下列几点不同： must表示的是说话人的主观看法，而have to则往往强调客观需要。如： The film is not interestingI really must go now I had to work when I was your age must只有一种形式，have to 则涉及人称、时态等方面的变化形式。 二者的否定意义大不相同。如： You mustnt go(带有很强的语气)表示禁止、不允许) You dont have to go(表示不必) 询问对方的意见时应用must，如： Must l clean all the room?e. 三个否定式can

16、t /couldnt不可能neednt 不必要mustnt 不准6. need a.需要，必须 作情态动词，只用于否定句和疑问句。-Need I leave now?-Yes, you must. /No, you neednt. You neednt hurry. You neednt have taken a taxi. He neednt buy such an expensive coat.didnt need to do 过去没有必要做，也没有做neednt have done b. 常作实义动词、行为动词，有时态、人称和数的变化.可以接名词，不定式和动名词作宾语(1) need+N

17、 . They are certain to need help. /I need no explanation. need no further discussion (2) sb. need(s) to do sb. doesnt need to My father needs to have a good rest.They did not need to arrive so early. =They neednt arrive so early. (3)Sth. need doing某事需要被做=sth. need to be done. Our classroom needs to

18、be cleaned.=Our classroom needs cleaning.My watch needs repairing. =My watch needs to be repaired.= My watch needs repairs. C. neednt have done本来没有必要做，却做了 You neednt have come. The meeting was put off/ delayed. -I didnt come to the meeting yesterday because of the heavy snow. - You didnt need to com

19、e. It was called off. 7. Should =ought to应该, a. 表义务、职责 Everyone should obey the rules of our school. You ought not to drive like that.Ought he not to see a doctor?b. 表可能性，多指预期的事，意为“（按道理）应该” She promised to come by 10:00. She should be here at any moment. c. 在表示命令、建议、要求的词后所跟的从句中，常用should + 动词原形 ，shou

20、ld 可以省略 suggest, advise, ask, recommend, propose, demand, request, require, order, commandThe doctor suggested that my father should give up smoking. d. Why，how+should， 表示说话人对某事不能理解，感到意外，惊异等，意为：竟会Why should you be so late today? (你今天怎么来得这么晚?)-Where is Betty living?(贝蒂住在哪里?)-How should I know?(我怎么会知道

21、呢?)How should I know where Betty lives?l dont know why you should think that l did it .(我真不知道你凭什么认为这件事是我干的。)e. 情态动词should用于第一人称时可以表示说话人的一种谦逊、客气、委婉的语气。如： I should think it would be better to try again(我倒是认为最好再试一试。) You are mistaken，I should say(依我看，你是搞错了。) I should advise you not to do that(我倒是劝你别这样做

22、。) This is something l should have liked to ask you(这是我本来想问你的。)f. 虚拟语气， 在主语从句中，“竟然”It is strange that you should forget his name.（竟然）If it should rain tomorrow, we would have to stay at home.(Should it rain tomorrow)（万一）g. should还可以用在if引导的条件从句中，表示一件事听起来可能性很小，但也不是完全没有可能。 相当于万一的意思。从句谓语由should加动词原形构成，主

23、句却不一定用虚拟语气。如：Ask her to ring me up if you should see her(你万一见到她，请让她给我打个电话。) If you should change your mind，please let us know(万一你改变主意，请通知我们。) 在if引导的虚拟条件句中，如果条件状语从句位于句首，且从句中含有should，则可以省略if，并用倒装结构。Should you change your mind, do let me know. =If you should change your mind, do let me know. 万一你改变了想法，一

24、定要告诉我。Should l be free tomorrow，I will come.= If I should be free tomorrow, I will come.(万一我明天有时间，我就来。) Should it rain this afternoon, 8. dare a. 可以作情态动词，(常用于否定、疑问句和条件句)一般不用在肯定句。有过去式，dared How dare you say Im unfair?He dare not speak English before such a crowd，dare he?b. 可以作实义动词，有人称和数的变化doesnt dare

25、 to do c. 作实义动词并用于否定句时，to可以省略I dare not go out alone.I dont dare (to) go out alone.He dares not climb the tree. 错He dare not climb the tree. He doesnt dare to climb the tree. I dare not to swim across this river错He does not dare (to) answerDont you dare (to)touch it?I wondered how he dared(to) say t

26、hat9. 情态动词+完成式acancould+have done用于疑问句或否定句时，表示对过去情况的推测。Could have done也可用于 肯定句，表示可能已经的意思；此外，它还可表示过去没有实现的可能性，意为本来可以(可能)。 You could have done better，but you didnt try your best I saw MrZhang just nowHe couldnt have gone to Beijingbmaymight+have done一般只用于肯定句或否定句，不用于疑问句，表示对过去情况不肯定的 推测，意为也许已经(没有)。might h

27、ave done还可用来表示本来可能，但实际上没发生的事。如： He may (might) have gone home He may not have finished the work You should not have climbed that hillYou might have killed yourself另外，might+ have done还可以表达本来应该或可以做但没有做某事之意，含有轻微的责备口吻。如： You might have given him more help，though you were busycmust+ have done只用于肯定句，表示对过去

28、情况肯定的推测，意为想必，一定做了某事。如： It must have rained last night，for the road was quite muddy.注意：如果要表示对过去情况否定的推测，不能用mustnt，要用cant have done或couldnt have done来表示：不可能做了某事。如： He cant have been to Beijing，for he knows too little about itd. neednt+ have done通常用于否定句或疑问句中，表示不必须做的事情却做了。如： You neednt have told her the

29、news, for I had told her earlier注意：didnt need to do表示没必要做而实际上也没有做某事。如： I didnt need to clean the windowsMy sister did iteshouldought to have done表示应该做的事情没做，shouldntought not to have done表示不应该做的事情却做了。如： You should have come to the meeting earlierfhad better+have done用于事后的建议，含轻微责备的口吻，意为当时最好做了某事。其否定式ha

30、d better not十have done表达相反的含义；如：You had better have started earliergwould rather十have done表示当时宁愿做了某事，would rather not have done表达相反含义，两者都含有后悔之意。如：I would rather have refused his offerI raised objections at the meeting, but now 1 would rather not have done that.h. would like to have done would love to have done表示未曾实现的过去某一打算，含有对曾经的遗憾，意为“本想要去做某事却没做成”比较: I would like to have gone to your party, but my mother fell ill and I had to look after her. I would like to go climbing this afternoon. -Why didnt you come to Johns party?- I