初中语法专题---情态动词

1、情态动词学习内容一、基本概念及特征概念：情态动词是一种本身有一定的词义，但要与动词原形及其被动语态一起使用，给谓语动词增添感情色彩，表示说话人对有关行为或事物的态度和看法，认为其可能、应该或必要等的动词。特征：不能单独作谓语，须和行为动词或系动词连用共同构成谓语； 无人称和数的变化（have to除外：has to/had to）； 后接动词原形（do/be）； 具有助动词作用（可用来构成否定句，疑问句及简明回答） 二、基本分类 只作情态动词的有：must, can (could), may (might) 可作情态动词也可作实义动词的有：need，dare 可作情态动词也可作助动词的有：wi

2、ll (would), shall (should) 具有情态动词某些特征的有：have to, ought to，had better3、 用法详解1、 情态动词基本用法1）can/could （1）表示能力，意为“能、会”。 Two eyes can see more than one.   两只眼比一只眼看得清。 Could the girl read she went to school?   这女孩上学前能识字吗？（2）表示请求或允许，多用于口语中，意为“可以”，相当于may。 You can go now. 你现在可以走了。 Can I ha

3、ve a look at your new pen?   我可以看一看你的新钢笔吗？ He asked whether he could take the book out of the reading-room.（3） 较委婉客气地提出问题或陈述看法。 Can (Could) you lend me a hand?   帮我一把好吗？ Im afraid we couldnt give you an answer today.   恐怕我们今天不能给你答复。注意：情态动词的过去式除了表示过去的时间这一用法外，更多时候表达一种比原形更

4、为委婉客气的语气。尤其在出现在宾语从句主句中时，并不影响从句的时态。2）may/might 表允许，might可以指过去时间，也可指现在时间，语气更委婉。 You may take whatever you like.   你喜欢什么就拿什么。 He told me that I might smoke in the room.   他告诉我可以在房间里抽烟。 May (Might) I ask for photo your baby?   我可以要一张你宝宝的照片吗？ 表示祝愿，常用于倒装结构中： May you succeed!

5、祝你成功！ May all your dreams come true! 愿你梦想成真！3）must 表示“必须”、“应当”。 We must love our country.我们要热爱祖国。 I must take a day off tomorrow.我明天必须请一天假。 must的否定式（mustnt）表示“不应该”、“不许可”、“不准”、“禁止”等，语气比较强烈。 You mustnt speak loudly in the library.不许在图书馆大声喧哗。 We mustnt waste our time.我们不应该浪费时间。4）need 作情态动词时，接动词原形。仅用于否定

6、句和疑问句，否定直接加not（neednt） Need we leave soon? Yes, you must.(No, you needn't) You needn't have hurried. 作实义动词时，接带to的不定式。否定和疑问借助助动词完成（如 did you need？didn't need） He needs to see a doctor. They didn't need to start so early.(do not need to do)5）shall表征询意见，用于第一、第三人称疑问句。 Shall I get some te

7、a?   我给你点茶好吗？ Shall the boy wait outside?  让那男孩在外面等吗？ What shall we do this evening?   我们今晚做什么？表说话人的意愿，有“命令、允诺、警告、决心”等意思，用于第二、三人称陈述句。 You shall do as I say.  按我说的做。（命令） You shall have my answer tomorrow. 你明天可以得到我的答复。（允诺） He shall be sorry for it one day,

8、I tell you.有一天他会后悔的，我告诉你。（警告） Nothing shall stop us from carrying out the plan.  什么也不能阻止我们执行这项计划。（决心）6）will 表意愿，用于各种人称陈述句。 I will do anything for you.   我愿为你做任何事。 None is so blind as those who wont see.   不愿看的人眼最瞎。 表请求，用于疑问句。 Will you close the window? Its a bit cold.&#

9、160;  请你把窗户关上好吗？有点冷。 Wont you drink some more coffee?   再来一点咖啡好吗？ 表示某种倾向或习惯性动作。 Fish will die out of water.   鱼离开水就不能活。 The door wont open.   这门打不开。7）should表义务。意为“应该”（某件事宜于做），用于各种人称。 You should be polite to your teachers.   你对老师应该有礼貌。 You shouldnt waste a

10、ny time.   你不应该浪费时间。表推测，意为“想必一定、照说应该、估计”等。 The film should be very good as it is starring first-class actors.   这部新电影是一流演员主演的，估计拍得很好。 They should be home by now.   照说他们现在应当已经到家了。8）would 表意愿：I said I would do anything for you.  我说过我愿意为你做任何事。 表委婉地提出请求、建议或看法。 Wou

11、ld you like another glass of beer? 再来杯啤酒好吗？ Would you mind cleaning the window?   请把窗户擦一下好吗？ They wouldnt have anything against it.   他们不会有什么反对意见。 表过去反复发生的动作或过去的一种倾向。 Every time she was in trouble, she would go to him for help.   她每遇到麻烦都会向她求助。他告诉我盒子打不开了。情态动词表猜测时：ca

12、n不肯。may不问，must肯定不否问。9）ought to表义务，意为“应该”（因责任、义务等该做），口气比should稍重。 You are his father. You ought to take care of him.   你是他父亲，应当管他。 You oughtnt to smoke so much.   你不应该抽这么多烟。表推测，暗含很大的可能，语气较弱。 Han Mei ought to know his telephone number. 韩梅该知道他的电话号码。 Theres a fine sunset; it oug

13、ht to be a fine day tomorrow.  今天有晚霞，明天应该是个好天。2、情态动词表猜测1）常考表猜测的词：must、may/might、can/could2）肯定猜测：must（一定，准是，必定）may（可能）might（也许，或许） He may be at home. 他可能在家 They might be having a meeting, but Im not sure.他们有可能在开会，不过我不肯定。 That lady must be an actress. 那位女士一定是个演员。 He hasnt come yet. He m

14、ust be ill.他还没来，准是病了。3）否定猜测：cant（不可能） couldnt（不可能） may not（可能不） might not（可能不） She may not know about it. 她可能不知道这件事。 He was afraid they might not agree with him. 他担心他们可能不同意他的意见。 It cant/couldnt be the headmaster, he has gone to America.它不可能是校长，他去美国了。4）猜测的时态：1 对一般情况的猜测：情态动词+动词原形 It may rain

15、 today.今天可能下雨。2 对过去情况的猜测：情态动词+have done如: If you were at the party, you must have seen Mary.你如果参加了聚会，准会见到玛丽。3 对正在进行的或即将发生的猜词：情态动词+be doing如：Lets hurry. They must be waiting for us .快！他们现在一定在等我们。【小试牛刀】1. John _ come to see us tonight, but he isnt very sure yet.A. may B. can C. has to D. must2. -He _

16、be in the classroom, I think.-No, he _ be in, I saw him go home a minute agoA. can, may not B. must, may not C. may, cant D. may, mustnt3. This history book _ be Bobs sisters, there is her name on it.A. must B. might C. cant D. mustnt答案：ACA3、 情态动词辨析1）can 和be able to （1）can只有过去式；be able to 根据be的变化可以有

17、多种时态 如：Mary can play the piano. She has been able to play it since she was 5. （2）表示天生的能力时，can 和 be able to 可以互换，但后者用得较少。但在谈到正在发生的事时，一般不用be able to。如：Look! I can stand on my hands. 瞧！我能倒立！ （3）如果要表示一个动作成功地完成了，必须用was able to, 而不能用could。（用在过去时中，could经常表示能够做某事，事实上不一定去做，而waswere able to则表示“过去做成了某事”。在否定句中两

18、者可通用。）如：He was able to leave Europe before the war began. 战争爆发前，他设法离开了欧洲。2）must和have to：must表示主观意志，而have to表示由于客观因素不得不做某事。We will have to ask Tom instead. 我们必须去问Tom了。（客观）We must work hard.我们必须努力工作。(主观)3）would和used toused to表示过去与现在或过去某时与后来的情况有不同，而would只表过去的情况。People used to think that the earth was f

19、lat.过去人们认为地球是平的。（现在人们不这么认为。）She would go out for a walk in the morning when she was in the country. 在乡下时，她总是在早晨去散会儿步。（可能现在仍有散步的习惯。）4.提问与回答表示客气或委婉的请求时用may, 用may回答显得冷淡、不客气。所以最好避之而改用热情、客气的答语。1）may提问May I come in? Yes, please. May I borrow your bike? Certainly.May I take this book out of the reading-roo

20、m? 我可以把书带出阅览室吗？No, you cant /mustnt. 不，你不能这么做。2）must提问Must I do my homework now? 我必须现在做作业吗？Yes, you must.是的，你非做不可。No, you neednt./dont have to. 不，你不必现在做。3）can提问Can/Could I use your computer? 我可以用一下你的电脑吗？Yes, you can. 是的，可以。 No, you cant./Im afraid not.4）need提问 Need I finish it now？ 我需要现在就完成吗？ Yes, y

21、ou must. 是的，必须现在完成。No, you needn't. 不，没必要。【小试牛刀】1. Must I do my homework at once? No, you_. A. needn't B. mustn't C. can't D. may not2. _ I take the newspaper away? No, you mustn't. You _ read it only here.A. Must; can B. May; can C. Need; must D. Must; must答案：AD 综合题库1.You _ stop

22、 when the traffic light turns red. A. can B. had better C. needD. must2. Shall we take a taxi? No, we . Its not far from here. A. cant B. mustnt C. shouldnt D. neednt3. Mom, must I clean my room now? No, you . You can do it tomorrow. A. cant B. neednt C. mustnt D. shouldnt 来4. There's enough tim

23、e for you to go to the airport. You_ hurry now.A. should B. needn't C. must D. can't5. Look! Is there your brother? No, it _ be him. He has gone to China.A. shouldnt B. wouldnt C. mustnt D. cant6. _I swim here?来网 I'm sorry. Children_swim alone here.来中&教A. Must; can'tB. May; mustC

24、. Can; mustn't D. Can't; can7. Is Maria knocking at the door? It _be her. She is in Australia now. A. may not B. needn't C. mustn't D. can't 8. Shall we take a taxi? No, we . Its not far from here.来*#te% A. cant B. mustnt C. shouldnt D. neednt9. You _ be happy with the strong pub

25、lic support youve received. Yes, youre right. Im really excited. A. may B. can C. must D. need10. Tom, you _ play with the knife. You_ hurt yourself A. won't; can't B. mustn't; may C. shouldn't; must D. can't; should11. My brother won the first prize in speech competition.来&源

26、:中教网% Congratulations! You be excited about that!中&国教育#出*版网 A. need B. must C. would D. can%出版网12. Must we wear our school uniform this afternoon? No, you . All of us will go on an outing. A. mustnt B. cant C. neednt D. couldnt13.Meng Fei had his arm broken while recording If You Are the One in

27、Beijing. Really? Then perhaps he host TV programs for some time. A. neednt B. mustnt C. shouldnt D. cant14. Have you decided which senior high school to choose? Not yet. I go to Moonlight School. A. must B. may C. need D. should15. I hear youve got a new iPhone 5S. _ I have a look? Yes, certainly. A

28、. May B. Do C. Shall D. Should16. The lady in this photo be over fifty! She looks so young!来源:*中#教&网A. mustnt B. mustC. cant D. can17. Must I do my homework now, Mum? . You can do it tomorrow. A. No, you neednt B. No, you mustntC. Yes, you need D. Yes, you must18. Dad, must I practice the piano

29、today? No, you . You may do it tomorrow.A. neednt B. mustnt C. shouldnt D. cant19. Excuse me, when are we going to have a picnic? Im not sure, Ask our monitor, please. He know.A. need B. can C. may D. shall20. Im afraid I need a pair of glasses. I _ hardly see the words on the blackboard. Thats terr

30、ible. You may have got poor eyesight.A. can B. must C. may D. need21. Last year I _ drive. I used to take the bus.A. could B. couldnt C. should D. shouldnt 中国%22.In Britain, you _ be 18 if you want to drive a car.   A. can  B

31、. must   C. may   D. might23. _ I try on those shoes in the window?中国_. They are just on show.中#A. Could; Yes, you can B. Can; Sorry, you couldntC. Could; Sorry, you cant D. Can; Yes, you could24. Must I turn down the radio now?中* No, you .A. mustntB. needntC. cantD. wont25. Do y

32、ou have any plans for this weekend?I'm not sure. I _ go climbing Mount Yuntai.A. must B. need C. may D. can26. _ I do the laundry first? No, you _. You can do your homework first. A. Must; mustn't B Can；mustn't来 C. Must; needn't D. May; needn't27. Must I wait for you here? No, you _. A. don't B. can't C .mustnt D. neednt28.Excuse me, can you tell me the way to the Peoples Park? Walk along