高中英語情態(tài)動(dòng)詞講解

1、Grammar: How many modal verbs do you know?can couldmay mightshall shouldmust will wouldought tohave to dare (darent)need (neednt) used to表示推測(cè)表示推測(cè)不表示推測(cè)不表示推測(cè)modal verbs表示推測(cè)表示推測(cè)一定，肯定一定，肯定 must一定不，不可能一定不，不可能cant, couldnt可能肯定句可能肯定句 may ,might ,could否定句否定句 may /might not疑問句疑問句 can ,could 都可以都可以 + do sth.表

2、示現(xiàn)在表示現(xiàn)在 be doing 表示正在發(fā)生的動(dòng)作表示正在發(fā)生的動(dòng)作 have done表示過去發(fā)生的動(dòng)作表示過去發(fā)生的動(dòng)作He must have a car now.must表示推測(cè)時(shí)，可以推測(cè)現(xiàn)在表示推測(cè)時(shí)，可以推測(cè)現(xiàn)在/正在發(fā)生正在發(fā)生的動(dòng)作的動(dòng)作/過去發(fā)生的動(dòng)作。過去發(fā)生的動(dòng)作。他一定有一輛車他一定有一輛車他一定在教室里做練習(xí)。他一定在教室里做練習(xí)。 他一定已完成了工作他一定已完成了工作He must have finished the work.He must be doing his exercises in the classroom.一定不，不可能一定不，不可能 cant

3、couldntHe cant be at home. He couldnt have said such a thing .他們一定不在圖書館讀書。他們一定不在圖書館讀書。約翰是很聰明的，他一定不會(huì)叫他兒子那約翰是很聰明的，他一定不會(huì)叫他兒子那樣做。樣做。 They cant be reading in the libraryJohn is very clever . He cannot have told his son to do that .可能可能肯定句肯定句 may ,might，could否定句否定句may might not（可能不）（可能不）疑問句疑問句 can ,couldv

4、他可能正在睡覺。他可能正在睡覺。These students may / might have seen the film before.否定句否定句The boy may / might not be watching TV at home. （現(xiàn)在）（現(xiàn)在）這個(gè)男孩可能沒在家看電視這個(gè)男孩可能沒在家看電視He may / might be sleeping nowv疑問句疑問句 How could he have forgotten such an important thing?這么重要的事他怎么能忘這么重要的事他怎么能忘了呢？了呢？ Its so late. Where can she

5、 have gone? 天晚了，她可能去哪兒了呢？天晚了，她可能去哪兒了呢？ Can you have left the watch at home?你你會(huì)不會(huì)把表丟在家里呢？會(huì)不會(huì)把表丟在家里呢？1 1Choose the best answers to complete the Choose the best answers to complete the following sentences:following sentences: 1. That man must be Sarahs husband.-No, he_ be her husband. She is still sing

6、le.A. cant B. mustnt C. may not D. ought to 2. Peter _come with us tonight, but he isnt very sure.A. must B. may C. can D. will 3.What_ it be? -It_ be a mail box, for it is moving. It_ be a car. A. can; cant; must B. can; can; must C. can; mustnt; must D. must; mustnt; can 4. Look, someone is coming

7、. Guess_ . -Jack. Hes always on time. A. who can it be B. who he may C. who he can be D. who it can be 5. I saw Mary in the library yesterday.-You_ her. She is still abroad.A. mustnt see B. cant have seen C. mustnt have seen D. couldnt see 6. David, you _play with the valuable bottle, you_ break it.

8、A. wont; cant B. mustnt; mayC. shouldnt; must D. cant; shouldnt 表示能力表示能力一表示能力一表示能力can, could, be able to can表示智力，體力方面的能力只能用表示智力，體力方面的能力只能用 現(xiàn)在現(xiàn)在或過去時(shí)。或過去時(shí)。 be able to通過努力克服困難作成事情通過努力克服困難作成事情, 能用能用于各種時(shí)態(tài)。于各種時(shí)態(tài)。 *was / were able to : 設(shè)法做成某事設(shè)法做成某事 相當(dāng)于相當(dāng)于 managed to do sth. succeeded in doing sth.。vcan與與be

9、 able to 用法區(qū)別常與句子時(shí)態(tài)有用法區(qū)別常與句子時(shí)態(tài)有關(guān)關(guān)v 1.現(xiàn)在時(shí)比較現(xiàn)在時(shí)比較v1) 表示表示”能力能力”時(shí)時(shí),be able to 不用于第二人不用于第二人稱稱,v You are able to do the work, I think. (X) 改用改用canvcan與感官動(dòng)詞與感官動(dòng)詞feel, hear, see, smell, taste連用時(shí)連用時(shí), can顯得可有可無顯得可有可無,因而失去了情態(tài)動(dòng)因而失去了情態(tài)動(dòng)詞的意義詞的意義,這種情況下這種情況下can不能用不能用be able to 代替代替ve.g., We can see beautiful flowe

10、rs and green trees here and there.vAnyone can see it is of no use.3) can) can與某些表示意念的動(dòng)詞如：與某些表示意念的動(dòng)詞如：understand, understand, remember, forget, hope, imagine, believe, remember, forget, hope, imagine, believe, supposesuppose等連用時(shí)，同樣沒有情態(tài)動(dòng)詞的意義，也等連用時(shí)，同樣沒有情態(tài)動(dòng)詞的意義，也不可用不可用be able tobe able to取代取代。e.g. I can

11、t believe there are so many I cant believe there are so many tall buildings now in my home town tall buildings now in my home town v v2.過去時(shí)比較過去時(shí)比較was/were able to 意含意含”經(jīng)過努力經(jīng)過努力” “憑借才能憑借才能” 獲得的獲得的”能力能力”常與常與”manage to ”相通相通 They were short of modern machines, but they were able to complete the project

12、 in time. 二表示允許vcan, could ,may, might might,could 表達(dá)更客氣、委婉、禮貌的請(qǐng)求語氣。表達(dá)更客氣、委婉、禮貌的請(qǐng)求語氣。Excuse me, could you tell me the way to the bus station?Could you help me?You can go now if you like.May I smoke in the room?三表示必須三表示必須ought to/should have to must *have to 能用于各種時(shí)態(tài)能用于各種時(shí)態(tài),且有人稱和數(shù)的變且有人稱和數(shù)的變化化. ought t

13、o 的否定式為的否定式為ought notto1.should 和和ought tov大多數(shù)情況下，含義基本相同，大多數(shù)情況下，含義基本相同，should主要主要看主觀看法，看主觀看法，ought to更多反映客觀情況，更多反映客觀情況，在談到法律，規(guī)定，義務(wù)時(shí)使用。在談到法律，規(guī)定，義務(wù)時(shí)使用。如：如：you should try your best to pass the entrance examinations. We ought to go and see Hellen, but I think we have no time.vShould 還可以表示驚訝，出乎意料的意思還可以表示

14、驚訝，出乎意料的意思 Why should he do such a thing?2.must與與have to 的用法的用法v前者側(cè)重于前者側(cè)重于主觀主觀意念意念,后者則用于表示后者則用于表示客觀客觀條件或義務(wù)條件或義務(wù),譯為譯為”只好只好” “不得不不得不”vmust用于用于疑問句疑問句，表示責(zé)備、抱怨的感情色彩，表示責(zé)備、抱怨的感情色彩，v意思為意思為“偏要偏要，硬要、干嘛，硬要、干嘛”； He must work to make his living. He has to beg for a living.Must沒有沒有過去式過去式,在單句中若是過去時(shí)在單句中若是過去時(shí),須用須用ha

15、d to e.g., He begged from door to door, for he had to do so to live若在從句中若在從句中,則可用則可用must來表示過去來表示過去e.g., He said he must manage to own a new house for Easter. 四表示虛擬should have done 本應(yīng)該做（而沒做）本應(yīng)該做（而沒做） should not have done 本不應(yīng)該做本不應(yīng)該做 He shouldnt have said such a thing .他當(dāng)時(shí)不他當(dāng)時(shí)不應(yīng)該說那種話。應(yīng)該說那種話。 We should

16、have studied last night, but we went to the concert instead 這種句式也能用這種句式也能用ought toneed not have done沒有必要做某事沒有必要做某事I need not have got up so early . 我本來我本來不必要那么早起床的（事實(shí)上早已起床）不必要那么早起床的（事實(shí)上早已起床）I need not have waited for the train for an hour. 我本來不必要等一個(gè)小時(shí)的火車。我本來不必要等一個(gè)小時(shí)的火車。（事實(shí)上已經(jīng)等了一個(gè)小時(shí)）（事實(shí)上已經(jīng)等了一個(gè)小時(shí)）3. c

17、ould have done它表示它表示“過去本來能夠過去本來能夠” 實(shí)際上沒能做實(shí)際上沒能做。 If you could have finished the task in time，you could have been promoted. 如如果你當(dāng)時(shí)能如期完成那任務(wù)的話，你可能已果你當(dāng)時(shí)能如期完成那任務(wù)的話，你可能已提升了（實(shí)際上沒有被提升）提升了（實(shí)際上沒有被提升） I could have laughed to hear him talk like that.聽他那樣講話，我差點(diǎn)笑出聲來。聽他那樣講話，我差點(diǎn)笑出聲來。v4.might have done虛擬式表示與過去事實(shí)虛擬式表

18、示與過去事實(shí)相反的假?zèng)]結(jié)果。相反的假?zèng)]結(jié)果。 If she had started a little earlier， she might have been in time for the train.如果如果她早點(diǎn)出發(fā)，她有可能及時(shí)趕上火車。她早點(diǎn)出發(fā)，她有可能及時(shí)趕上火車。(實(shí)際實(shí)際上沒有早出發(fā)，便沒有趕上火車上沒有早出發(fā)，便沒有趕上火車) It might have been better to stop then.如果那時(shí)就停止的話，也許比較好。如果那時(shí)就停止的話，也許比較好。5would have done v它表示的是與過去事實(shí)相反之假設(shè)的結(jié)果，它表示的是與過去事實(shí)相反之假設(shè)的結(jié)

19、果，意思是意思是“當(dāng)時(shí)就會(huì)當(dāng)時(shí)就會(huì)了了”而實(shí)際上沒有而實(shí)際上沒有 I would have helped you if I had known of your difficulties . If it hadnt rained yesterday, we would have gone climbing .假如昨天沒下雨，我假如昨天沒下雨，我們就去了。（實(shí)際上沒有去）。們就去了。（實(shí)際上沒有去）。五其他情態(tài)動(dòng)詞用法五其他情態(tài)動(dòng)詞用法情態(tài)動(dòng)詞情態(tài)動(dòng)詞dare, need 通常用于否定句或疑問句通常用于否定句或疑問句 Who dare do it? Dare you go out alone ?d

20、are, need 還可用作行為動(dòng)詞，可以用于各還可用作行為動(dòng)詞，可以用于各種句式，后面可跟加種句式，后面可跟加to的不定式的不定式 A. who dare do it? B. He dares to do it.A. He neednt do it B. he needs to do it 上述句子中A句為含情態(tài)動(dòng)詞的句子，B句中dare. need 均為行為動(dòng)詞 注意動(dòng)詞注意動(dòng)詞 dare 的某些特殊用法。的某些特殊用法。1）固定句型固定句型I dare say. 我敢說我猜想以為我敢說我猜想以為 Dont worry, sir. I dare say, nobody will come

21、again. 2) 作為行為動(dòng)詞作為行為動(dòng)詞dare在在 否定句中后面否定句中后面的可以省略的可以省略 He doesnt dare (to) go to the forest at night. The man never dares (to) do anything without his owners permission 5. dare “敢敢”，多用在否定或疑問句中。，多用在否定或疑問句中。 The little girl dare not speak in public. 小女孩不敢在公眾小女孩不敢在公眾面前說話。面前說話。 Dare you catch the little ca

22、t? 你敢抓小貓嗎你敢抓小貓嗎? dare 除用作情態(tài)動(dòng)詞外，更多的是當(dāng)實(shí)義動(dòng)詞使用，除用作情態(tài)動(dòng)詞外，更多的是當(dāng)實(shí)義動(dòng)詞使用， 用法同實(shí)義動(dòng)詞一樣，要考慮人稱，單復(fù)數(shù)，時(shí)態(tài)等。用法同實(shí)義動(dòng)詞一樣，要考慮人稱，單復(fù)數(shù)，時(shí)態(tài)等。 Do you dare to walk in the dark? 你敢黑夜走路嗎？你敢黑夜走路嗎？ He doesnt dare to tell the teacher what happened that day. 他不敢告訴老師那天發(fā)生的事。他不敢告訴老師那天發(fā)生的事。willI. 表現(xiàn)在經(jīng)常發(fā)生的情況表現(xiàn)在經(jīng)常發(fā)生的情況e.g., The man will go

23、to work every day.(= The man goes to work every day 后者更常用后者更常用)The door wont open. II.表示表示“決心決心”“”“意愿意愿”“”“可能可能”等等e.g If you will come tonight, hell meet you, I think. This will be the book you are looking for.Will you come in ? (=Will you please come in?)III. 若表示過去，則用若表示過去，則用woulde.g., He would tak

24、e a walk after supper when he lived in the country.He said he would help that girl.表示表示“過去常常過去常常”除了用除了用would，還可以用，還可以用used to，不過后者常常含有不過后者常常含有“現(xiàn)在不現(xiàn)在不”之意。之意。e.g., When young, he would go out for a trip on Sundays.(Now maybe still does)When young, he used to go out for a trip.(But now he doesnt)此外，此外，

25、would表示表示“過去常常過去常?！睍r(shí)后面動(dòng)詞須是某種時(shí)后面動(dòng)詞須是某種行為或動(dòng)作，不能是靜態(tài)動(dòng)詞行為或動(dòng)作，不能是靜態(tài)動(dòng)詞 。e.g., Near the village, there _ be a stream.A. would B. used toWould更多的用來表示語氣而不是時(shí)態(tài)更多的用來表示語氣而不是時(shí)態(tài) Will/would you please do., Would you like to do., Would you mind doing. 都表示建議、詢問、請(qǐng)求等。都表示建議、詢問、請(qǐng)求等。e.g., Would/ Will you mind opening the w

26、indows?I would / will do anything for you , sir.有時(shí)甚至只能用有時(shí)甚至只能用would而不用而不用wille.g., I would like. Would you like.?They would love. He would rather shallI. 表示詢問或征求別人的意見看法用于一、三人稱表示詢問或征求別人的意見看法用于一、三人稱e.g., Shall I open the door?要我開門嗎？要我開門嗎？Shall he stay here for the night? 讓他留下過夜嗎？II.表示說話人的允諾，警告，命令，威脅等，

27、用于二、表示說話人的允諾，警告，命令，威脅等，用于二、三人稱三人稱e.g., If you work well ,you shall be well paid He says he wont come, but I say he shall. If you go there again, you shall lose what youve got.vIII表示規(guī)章，知識(shí)，預(yù)言等vEach competitor shall wear a number.vThe rules shall be obeyed.6反義疑問句反義疑問句在反意疑問句中，當(dāng)附屬部分含有表示推測(cè)意義的在反意疑問句中，當(dāng)附屬部分

28、含有表示推測(cè)意義的must, cant時(shí)，疑問部分的助動(dòng)詞應(yīng)與時(shí)，疑問部分的助動(dòng)詞應(yīng)與must ,cant后后面的動(dòng)詞在非推測(cè)情況下的用法保持一致。面的動(dòng)詞在非推測(cè)情況下的用法保持一致。 1. He must be a worker, ? 2. It must have rained last night, ? 3. You must have learned English for many years, ?4. He cant be a teacher, ? 5. She cant have finished her homework, ? didnt ithavent youisnt heis hehas she1. A computer _ think for itself; it must be told what to do. A. cant B. couldnt C. may not D. might not2. The fire spread through the hotel very quickly but everyone _ get out. A. had to B. would C. could D. was