情態(tài)動詞(初中版)

1、精選優(yōu)質(zhì)文檔-傾情為你奉上什么是助動詞 協(xié)助主要動詞構(gòu)成謂語動詞詞組的詞叫助動詞（Auxiliary Verb）。被協(xié)助的動詞稱作主要動詞（Main Verb）。助動詞自身沒有詞義，不可單獨使用。 助動詞(auxiliary)主要有兩類：基本助動詞(primary auxiliary)和情態(tài)助動詞(modal auxiliary)。基本助動詞有三個：do, have和be；情態(tài)助動詞有十三個：may, might; can, could; will, would; shall, should; must, need, dare, used to, ought to. 上述兩類助動詞的共同特征是

2、，在協(xié)助主動詞構(gòu)成限定動詞詞組時，具有作用詞的功能： ² 助動詞be的用法 1） be +現(xiàn)在分詞，構(gòu)成進(jìn)行時態(tài)，例如：They are having a meeting.他們正在開會。English is becoming more and more important. 英語現(xiàn)在越來越重要。2)be + 過去分詞，構(gòu)成被動語態(tài)，例如：The window was broken by Tom.窗戶是湯姆打碎的。English is taught throughout the world.世界各地都教英語。3） be + 動詞不定式，可表示下列內(nèi)容：表示最近、未來的計劃或安排，例如：

3、 He is to go to New York next week.他下周要去紐約。 We are to teach the fresh persons.我們要教新生。說明： 這種用法也可以說成是一種將來時態(tài)表達(dá)法。 ² 助動詞have的用法 1）have +過去分詞，構(gòu)成完成時態(tài)，例如：He has left for London.他已去了倫敦。By the end of last month, they had finished half of their work.2）have + been +現(xiàn)在分詞，構(gòu)成完成進(jìn)行時，例如：I have been studying Engl

4、ish for ten years.3）have+been +過去分詞，構(gòu)成完成式被動語態(tài)，例如：English has been taught in China for many years. ² 助動詞do 的用法 1） 構(gòu)成一般疑問句，例如：Do you want to pass the CET? 你想通過大學(xué)英語測試嗎？Did you study German? 你們學(xué)過德語嗎？2） do + not 構(gòu)成否定句，例如：I do not want to be criticized.我不想挨批評。He doesn't like to study.他不想學(xué)習(xí)。In the

5、 past, many students did not know the importance of English.3)構(gòu)成否定祈使句，例如：Don't go there.不要去那里。Don't be so absent-minded.不要這么心不在焉。說明： 構(gòu)成否定祈使句只用do，不用did和does。4） 放在動詞原形前，加強(qiáng)該動詞的語氣，例如：Do come to my birthday party.一定來參加我的生日宴會。I did go there.我確實去那兒了。I do miss you.我確實想你。5） 用于倒裝句，例如：Never did I hear

6、of such a thing.我從未聽說過這樣的事情。Only when we begin our college life do we realize the importance of English.只有在開始大學(xué)生活時我們才認(rèn)識到英語的重要性。說明： 引導(dǎo)此類倒裝句的副詞有never, seldom, rarely, little, only, so, well等。6） 用作代動詞，例如：- Do you like Beijing?-你喜歡北京嗎？- Yes, I do.-是的，喜歡。（do用作代動詞，代替like Beijing.）He knows how to drive a c

7、ar, doesn't he?情態(tài)助動詞的意義和用法情態(tài)助動詞從最普通的意義上來說，是修飾分句意義的一種方式，它可以反映說話者對其表述是否真實和可能的程度作出判斷。但不同的情態(tài)助動詞本身所包含的意義和用法又不同，下面逐個分析。Ø can和could的用法l 表示能力或客觀可能性，還可以表示請求和允許。如：Can you finish this work tonight?Man cannot live without air.注意：could也可表示請求，預(yù)期委婉，主要用于疑問句，不可用于肯定句，答語應(yīng)用can（即could不能用于現(xiàn)在時態(tài)的簡略答語中）。如： Could I

8、come to see you tomorrow? Yes, you can. （否定答語可用No, Im afraid not.） can表示能力時，還可用be able to代替。如： Ill not be able to come this afternoon.l 表示驚異、懷疑、不相信的態(tài)度。（主要用在否定句、疑問句或驚嘆句中）Can this be true? How can you be so careless! This cannot be done by him.l “can(could) + have + 過去分詞”的疑問或否定形式表示對過去發(fā)生的行為懷疑或不肯定。如：He

9、cannot have been to that town.Ø may和might的用法l 表示許可。表示請求、允許時，might比may的語氣更委婉一些，否定回答時要用mustnt表示“不可以”、“禁止”、“阻止”之意。如：You may drive the car. Might I use your pen? No, you mustnt.l 用May I . 征詢對方許可在文體上比較正式，在口氣上比較客氣。在日?？谡Z中，用Can I . 征詢對方意見在現(xiàn)代口語中更為常見。l 用于祈使句中表示祝愿。如：May you succeed!l 表示推測、可能（疑問句不能用于此意）。如：

10、He may be very busy now.l “may(might) + have + 過去分詞”表示對過去發(fā)生的行為的推測。如：He may not have finished the work.Ø must和have to的用法l 表示必須、必要。如：You must come in time.回答must引出的問句時，如果是否定的回答，不能用mustnt，而要用neednt或dont have to。Must we hand in our exercise books today?Yes, you must. (No, you dont have to.)l “must

11、be + 表語”的結(jié)構(gòu)表示推測，它的否定或疑問式用can代替must。This must be your pen.l “must + have + 過去分詞”的結(jié)構(gòu)常用在肯定句中，表示對過去發(fā)生的行為的推測。它的否定或疑問式用can代替must。He must have been to Shanghai.l have to的含義與must相似，兩者往往可以互換使用，但have to有各種形式，隨have的變化而定。must與have to有下列幾點不同：i. must表示的是說話人的主觀看法，而have to則往往強(qiáng)調(diào)客觀需要。如：The play is not interesting. I

12、really must go now.I had to work when I was your age.ii. must一般只表現(xiàn)在，have則有更多的時態(tài)形式。iii. 二者的否定意義不大相同。如：You mustnt go. 你可不要去。You dont have to go. 你不必去。iv. 詢問對方的意愿時應(yīng)用must。如：Must I clean all the room?Ø dare和need的用法l need表示“需要”或“必須”，作情態(tài)動詞時，僅用于否定句或疑問句中，在肯定句中一般用must, have to, ought to,或should代替。如：You n

13、eednt come so early.Need I finish the work today?Yes, you must.l 注意：neednt + 不定式的完成式“表示本來不必做某事而實際上做了某事”。如：You neednt have waited for me.l Dare作情態(tài)動詞時，主要用于疑問句、否定句和條件從句中，一般不用在肯定句中。如：How dare you say Im unfair？He darent speak English before such a crowd, dare he?l Dare和need常用作實義動詞，有時態(tài)、人稱和數(shù)的變化，所不同的是，作實義動

14、詞時，在肯定句中，dare后面通常接帶to的不定式，在否定和疑問句中，dare后面可接帶to或不帶to的不定式。如：I dare to swim across this river.He does not dare (to) answer.I wondered he dare (to) say that.He needs to finish it this evening.Ø shall和should的用法l Shall用于第一人稱，表示征求對方的意愿。如：What shall we do this evening?l Shall用于第一、第三人稱疑問句中，表示說話人征求對方的意見或

15、向?qū)Ψ秸埵?。如：Shall we begin our lesson?When shall he be able to leave the hospital?l Shall用于第二、第三人稱，表示說話人給對方命令、警告、允諾或威脅。如：You shall fail if you dont work harder. （警告）He shall have the book when I finish reading. （允諾）He shall be punished. （威脅）l Should表示勸告、建議、命令，其同義詞是ought to；在疑問句中，通常用should代替ought to。如：Yo

16、u should go to class right away.Should I open the window?Should的含義較多，用法較活，請看下面的句子： I should think it would be better to try it again. 我倒是認(rèn)為最好再試一試。 You are mistaken, I should say. 依我看，你是搞錯了。 I should advise you not to do that. 我倒是勸你別這樣做。 This is something I should have liked to ask you. 這是我本來想問你的。從以上

17、例句可以看出：情態(tài)動詞should用于第一人稱時可以表示說話人的一種謙遜、客氣、委婉的語氣。Should還可以用在if引導(dǎo)的條件從句，表示一件事聽起來可能性很小，但也不是完全沒有可能。相當(dāng)于“萬一”的意思。從句謂語由should加動詞原形構(gòu)成，主句謂語卻不一定用虛擬語氣。如： Ask her to ring me up if you should see her. 你萬一見到她，請讓她給我打個電話。 If you should change your mind, please let us know. 萬一你改變主意，請通知我們。 Should I (If I should) be free

18、tomorrow I will come. 萬一我明天有時間，我就來。此外，Why(or How) + should結(jié)構(gòu)表示說話人對某事不能理解，感到意外、驚異等意思。意為“竟會”。如： Why should you be so late today? 你幾天怎么來得這么晚？ Where is Betty living? 貝蒂住在哪里？ How should I know? 我怎么會知道呢？ I dont know why you should think that I did it. 我真不知道你憑什么認(rèn)為這件事是我干的。l “should + have + 過去分詞”結(jié)構(gòu)一般表示義務(wù)，表示

19、應(yīng)該做到而實際上沒有做到，并包含一種埋怨、責(zé)備的口氣。如：She should have finished it.Ø will和would的用法l 表示請求、建議等，would比will委婉客氣。如：Would you pass me the book?l 表示意志、愿望和決心。如：I will never do that again.They asked if we would do that again.l 用“will be”和“will(would) + have + 過去分詞”的結(jié)構(gòu)表示推測，主要用于第二、三人稱。前者表示對目前情況的推測，后者表示對已經(jīng)完成的動作或事態(tài)的推

20、測。如：This will be the book you want.He will have arrived by now.The guests would have arrived by that time.I thought you would have finished this by now.l Would可表示過去反復(fù)發(fā)生的動作或某中傾向。Would表過去習(xí)慣時比used to正式，并沒有“現(xiàn)已無此習(xí)慣”的含義。如：The wound would not heal.During the vacation he would visit me every week.l 表料想或猜想。如

21、：It would be about ten when he left home.What would she be doing there?I thought he would have told you all about it.Ø ought to的用法l Ought to表示應(yīng)該。如：You ought to take care of him.l 表示推測。注意與must表示推測時的區(qū)別：He must be at home by now. （斷定他已到家）He ought to be home by now. （不十分肯定）This is where the oil mus

22、t be. （比較直率）This is where the oil ought to be. （比較含蓄）l “ought to + have + 過去分詞”表示過去應(yīng)做某事而實際未做。如：You ought to have asked him (but you didnt).這時，ought to和should可以互相換用。Ø used to，had better，would rather的用法l Used to表示過去的習(xí)慣動作或狀態(tài)，現(xiàn)在已不存在，在間接引語中，其形式可不變。如：He told us he used to play football when he was yo

23、ung.在疑問句、否定句、否定疑問句或強(qiáng)調(diào)句中，可有兩種形式：疑問句Did you use to go to the same school as your brother?Used you to go to the same school as your brother?否定句I usednt to go there.I didnt use to go there.used nt 亦可拼作usednt，但發(fā)音皆為ju:znt。否定疑問句Usednt you to be interested in the theatre?Didnt you use to be interested in th

24、e theatre?強(qiáng)調(diào)句I certainly used to smoke, but it was a long time ago.I certainly did use to smoke, but it was a long time ago.其反意疑問句或簡略回答中，也有兩種形式：She used to be very fat, didnt she? （正式）/ use(d)nt she? （口語）Did you use to play chess? Yes, I did.Used you to get up early in the morning? Yes, I did. (Yes,

25、 I used to.)Ø Had better意為“最好”，后接不帶to的不定式。如：We had better go now.Yes, we had (wed better / we had better).Hadnt we better stop now? (Had we better not stop now?)I think Id better be going. （用于進(jìn)行時態(tài)，表“最好立即”）You had better have done that. （用于完成時態(tài)，表未完成動作。注：had best與had better同意，但較少用。You had better

26、用于同輩或小輩，對長輩不可用。Ø Would rather意為“寧愿”，表選擇，后接不帶to的不定式。如：Would you rather work on a farm?Wouldnt you rather stay here?No, I would not. Id rather go there.Ø 由于would rather表選擇，因而后可接than。如：I would rather work on a farm than in a factory.I would rather watch TV than go to see the film.I would rath

27、er lose a dozen cherry trees than that you should tell me one lie.Id rather you didnt talk about this to anyone. （句中的d rather不是情態(tài)動詞，would在此是表愿望的實義動詞）Ø need和dare的用法need和dare既可用作情態(tài)動詞，也可用作實義動詞。用作情態(tài)動詞時，主要用于否定句和疑問句。用作實義動詞時，可用于各種句式。1.用作情態(tài)動詞-Need I come?  -Yes, you must.  -我需要來嗎？  -需要。Y

28、ou neednt telephone him now.   你現(xiàn)在不必打電話給他。I dont think you need worry.   我想你不必發(fā)愁。She dare not go out alone at night.   她晚上不敢一個人出去。How dare you say Im unfair?   你竟敢說我不公平？2. 用作實義動詞You dont need to do it yourself.   你不必親自做這件事。We need to tell them the ne

29、ws.   我們需要把這消息告訴他們。The table needs painting (to be painted.).   桌子需要油漆一下。We should dare to give our own opinion.   我們要敢于提出自己的觀點。He did not dare (to) look up.   他不敢抬頭看。I dare day hell come again.   我想他會再來的。（I dare say為固定習(xí)語）² 情態(tài)動詞后跟完成式和進(jìn)行式的用法1.情態(tài)動

30、詞后跟完成式，表“應(yīng)當(dāng)已經(jīng)”，“想必已經(jīng)”，“本來可以”等意。I should have finished the work earlier.   我應(yīng)當(dāng)早一點完成這項工作的。He isnt here. He must have missed the train.   他還未到，一定是沒趕上火車。Where can (could) he have gone?   他能到那里去了呢？You may (might) have read about it.   你可能在報上已經(jīng)讀到這件事了。You could (migh

31、t) have been more careful.   你本來可以更細(xì)心的。He neednt have worried about it.   他本不必為此事?lián)?。There was a lot of fun at yesterdays party. You ought to have come, but why didnt you?   昨天的聚會非常有意思。你本應(yīng)該來，為何不來呢？2. 情態(tài)動詞后跟進(jìn)行式，表示“想必正在”，“可能正在”，“應(yīng)當(dāng)正在”等意。Its twelve oclock. They must be havi

32、ng lunch.   現(xiàn)在是十二點。他們一定正在吃飯。They may be discussing this problem.   他們可能正在論討這個問題。He cant be telling the truth.   他說的不可能是真話。She shouldnt be working like that. Shes still so weak.  她不應(yīng)當(dāng)那樣干，她身體仍那么虛。情態(tài)動詞表推測的用法小結(jié)（一）情態(tài)動詞表推測的三種句式 1.在肯定句中一般用must (一定)，may（可能），might / could（也

33、許，或許）。（1）He must/may/might know the answer to this question? 他一定/可能/也許知道這個問題的答案。 （2）It is cold in the room. They must have turned off the heating. 屋里很冷，他們肯定把暖氣關(guān)了。 2.否定句中用cant / couldnt(不可能), may not/might not(可能不)。 （1）It cant/couldnt be the headmaster. He has gone to America. 這不可能是校長，他去美國了。 （2） He m

34、ay not/might not know the scientist. 他也許不認(rèn)識那位科學(xué)家。 3.疑問句中用can/could (能?)。 （1）Could he have finished the task? 他可能把任務(wù)完成了嗎？ （2）Can he be at home now? 他現(xiàn)在能在家嗎？ 注：以上三種句式中情態(tài)動詞的語氣按程度都是依次遞減的。Might, could并非may, can的過去式，而表示語氣較為委婉或可能性較小。 （二）情態(tài)動詞表推測的三種時態(tài) 1.對將來情況的推測，用“情態(tài)動詞 + 動詞原形”。 （1）She must / may / might / co

35、uld arrive before 5. 5:00前她一定/可能/也許到。 （2）She must/may/might/could walk miles and miles among the hills without meeting anyone. 她一定/可能/也許會在山里一連走好幾英里而遇不到一個人。 2.對現(xiàn)在或一般情況的推測，用“情態(tài)動詞 + be”，“情態(tài)動詞 +be doing”或“情態(tài)動詞 + 動詞原形”。 （1）He must / may / might / could be listening to the radio now. 他一定/可能/也許正在聽收音機(jī)。 （2）H

36、e cant ( couldnt ) / may ( might ) not be at home at this time. 這個時候他不可能/可能不在家。 （2） Mr. Bush is on time for everything .How can ( could ) he be late for the opening ceremony ? 3.對過去情況的推測，用“情態(tài)動詞 + have +過去分詞”。 （1）It must / may / might / could have rained last night .The ground is wet. 地濕了，昨晚肯定/可能/也許下雨了。 （2）The door was locked. He can ( could