1、【精品文檔】如有侵權(quán)，請聯(lián)系網(wǎng)站刪除，僅供學(xué)習(xí)與交流情態(tài)動詞講解can,may, should,must,ought to區(qū)別及用法,練習(xí)加詳解.精品文檔.一、情態(tài)動詞主要用來表示說話人的看法、態(tài)度等1. can (could)1) 表示能力，could主要指過去時間。例如： Two eyes can see more than one. 兩只眼比一只眼看得清。 Could the girl read before she went to school? 這女孩上學(xué)前能識字嗎？ 因?yàn)閏an不能和其他助動詞連用，所以表示將來式時用will be able to 例：You will be abl

2、e to skate after you have practiced it two or three times.注意：Can表示一貫的能力 ，be able to表示客觀能力和通過努力可以達(dá)到的能力 I cant swim. But I am sure I will be able to swim through more practicing. The fire spread through the hotel, but everyone was able to get out2) 表示允許。例如： Can I have a look at your new pen? 我可以看一看你的新

3、鋼筆嗎？ He asked whether he could take the book out of the readingroom. 他問他可不可以把書帶出閱覽室。3) 表驚異、懷疑、不相信等態(tài)度。主要用于否定句、疑問句或感嘆句中。例如： Where can (could) they have gone to? 他們會去哪兒了呢？ How can you be so careless? 你怎么這么粗心？4) 比較委婉客氣地提出問題或陳述看法。例如： Can (Could) you lend me a hand? 幫我一把好嗎？. Im afraid we couldnt give you

4、an answer today. 恐怕我們今天不能給你答復(fù)。Could/can+have done 結(jié)構(gòu)表示對過去發(fā)生的事情的“懷疑”或“不肯定”。 could 加完成式還用于肯定句時一般表過去可能完成而卻未完成的動作。Can they have won the basketball match？他們贏了那場籃球賽嗎？What you referred to just now can have made her very sad.你剛剛所談到的可能令他很傷心。You could have completed the task a little earlier.你本來能早點(diǎn)完成任務(wù)的。（但事實(shí)上

5、并沒有提前完成任務(wù)）I could have passed my examination easily but I made too many stupid mistakes.我本可以輕易通過考試，但我犯了太多不該犯的錯誤。如表具體做某一件事的能力時，則須用 be able to .He was able to translate the article without a dictionary.他可以不用詞典翻譯那篇文章。2may (might) 1) 表允許，might可以指過去時間，也可指現(xiàn)在時間，語氣更委婉。例如： You may take whatever you like.你喜歡什

6、么就拿什么。 May (Might) I ask for a photo of your baby? 我可以要一張你寶寶的照片嗎？2) 在回答以may引起的問句時，多避免用這個詞，而用其它方式，如Yes, please. / Certainly. / Please dont. / Youd better not. / No, you mustnt.等，以免顯得太嚴(yán)峻或不客氣。3)may /might 推測性用法 可能He may be right. He may not come today (可能不) He may /might come tomorrow.注意 : (1)只用于肯定和否定句

7、中,不用于疑問句中。 (2) might 比may可能性更小 He might get a job. He may get a job. (3) may no 可能不 can not不可能 He may not come . He cant come4)表建議（可和as well 連用）You may（might）as well stay where you are. 你還是原地待著好。（may as well 有“還是的好”的含義）5)表祝愿May you be happy!6). might表過去的“可能”和“允許”多用于間接引語。She said that he might take h

8、er dictionary. 她說他可以拿她的詞典去用。除在間接引語中外，might一般不表示過去的“可能”與“許可”。表過去的“可能”可用could，表過去的“許可”可用were (was) allowed to。7)might表現(xiàn)在的“可能”，其可能性要比may小。Electric irons could be dangerous; they might give you a severe shock.8)may (might) + have +done 表示對過去發(fā)生行為的推測，含有“想必”、“也許是”的意思。It may have been true. 這事也許是真的。He might

9、 not have settled the question. 他可能尚未解決那個問題。3. must1)表示義務(wù)。意為“必須”（主觀意志）。例如：We must do everything step by step .我們必須按部就班地做一切事情。Why must you always bother me? 為什么你偏要打擾我呢。2)must be + 表語的結(jié)構(gòu)，通常表示猜測，含有“一定”之意。（只用在肯定句中）He must be an honest boy.他一定是個誠實(shí)的男孩This must be your room.這一定是你的房間。3)must 的否定式有兩個：當(dāng)回答由must

10、引起的問題時，否定答復(fù)要用neednt或dont have to 表示“不必”、“無須”、“用不著”、“不一定”的意義。當(dāng)表示“不應(yīng)該”、“不許可”、“禁止”時，就用must not。Must I go tomorrow?明天我必須去嗎？Yes, please. No , you neednt. 4)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)生行為的推測，含有“一定”、“準(zhǔn)是”的意思。否定和疑問句用can。She must have studied English before.她以前一定學(xué)過英語。5) 區(qū)別：have to的含義與must是很接近的,只是have t

11、o 比較強(qiáng)調(diào)客觀需要，must著重說明主觀看法。I must clean the room.（主觀想法） I have to clean the room.（客觀需要）另外，have to 能用于更多時態(tài)：We had to be there at ten .我們得在十點(diǎn)鐘到那里。We will have to reconsider the whole thing.have to 的否定式：dont have to do 表示“不必做”之意。4.shall 1) 表征詢意見，用于第一、第三人稱疑問句。例如： Shall I get you some tea? 我給你點(diǎn)茶好嗎？ Shall th

12、e boy wait outside? 讓那男孩在外面等嗎？2)表說話人的意愿，有“命令、允諾、警告、決心”等意思，用于第二、第三人稱陳述句。例如： You shall do as I say. 按我說的做。（命令） You shall have my answer tomorrow. 你明天可以得到我的答復(fù)。（允諾） He shall be sorry for it one day, I tell you. 有一天他會后悔的，我告訴你。（警告） Nothing shall stop us from carrying out the plan. 什么也不能阻止我們執(zhí)行這項(xiàng)計(jì)劃。（決心）5. s

13、hould1)用于第一人稱疑問句中詢問對方的意愿，但語氣較委婉溫和，如：What should we do now? 我們現(xiàn)在該怎么辦？2)表示應(yīng)該、必須，常與must 換用。例如：We should (must) master a foreign language at least.3）（表示不確定）萬一。例如： If I should see him, Ill tell him. 萬一我見到他，我就告訴他。 If it should rain tomorrow, the sports meeting would be postponed. 萬一明天下雨。4)“should+be+表語”的結(jié)

14、構(gòu)，表示推測或驚奇。例如：They should be back by now. 他們現(xiàn)在應(yīng)該回來了吧。I am sorry that she should be so careless. 我感到遺憾她竟會那樣粗心。5)“should+have+過去分詞”的結(jié)構(gòu)，表示過去該做而實(shí)際上尚未做的動作或行為；其否定則表示發(fā)生了不應(yīng)該發(fā)生的行為。其同義結(jié)構(gòu)“ought to have +過去分詞”,表示過去“早應(yīng)該”、“本當(dāng)”之意，語氣較強(qiáng)。例如：I should have thought of that. 這一點(diǎn)我是應(yīng)當(dāng)想到的。（但沒想到）They should not have left so s

15、oon.他們不應(yīng)當(dāng)走得這么早。（但已走了）6) 在“It is natural (strange, natural, necessary, surprised, impossible, important ) that”句型中，主語從句中的謂語動詞要用should +動詞原形”表示“理所當(dāng)然”、“奇怪”、“必要”、“驚異”等的意思。在lest（以免）、for fear (that) (以防)、in case（以備萬一）等之后也要用should+動詞原形;在advise, sugest, order, demand, request 等的從句中should+do”例如：It is necessa

16、ry that he(should) be sent there at once.It is strange that he should say so. 他會說這樣的話真是奇怪。6.will和would的用法1）表示意志，決心或愿望。例如：Surely we will support all the people in the world in their struggle for peace.He would not let me try it . 他不肯讓我去試。2）will表示經(jīng)常性、習(xí)慣性、傾向性，would表示過去的習(xí)慣行為。He will sit there hour after

17、 hour looking at the traffic go by.He would come to see me when he was in Beijing.3）用于第二人稱作主語的疑問句中，表示對對方的請求，would的語氣比will委碗Would/will you kindly tell me the way to the station? 請問到火車站怎么走？4）表可能性This will be the book you are looking for. 這可能就是你要找的書。She would be about 60 when she died.7.ought to 表義務(wù)，意為

18、“應(yīng)該”（因責(zé)任、義務(wù)等該做），口氣比should稍輕。例如： You are his father. You ought to take care of him.你是他父親，應(yīng)當(dāng)管他。 You oughtnt to smoke so much. 你不應(yīng)該抽這么多煙。8. used to1）表示過去的習(xí)慣動作或狀態(tài)，現(xiàn)在不復(fù)發(fā)生或存在。疑問式和否定式有兩種。例如：i There used to be a building at the street corner, but it has been pulled down. I usednt (didnt use) to smoke. 我過去不抽

19、煙。j F Used you (Did you use) to go to school on foot? 你過去常步行去學(xué)校嗎？2）used to +v, be used to +v-ing和be used to +v used to +v意為“過去常?！?，“過去一直”；be used to +v-ing / n（名詞）意為“習(xí)慣于”；be used to +v意為“被用來（做某事）”。例：He used to smoke. Now he doesnt. Hes quite used to hard work / working hard.The knife is used to cut b

20、read.9.特殊情態(tài)動詞need和dare的用法：need和dare既可用作情態(tài)動詞，也可用作實(shí)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(shí)義動詞時，可用于各種句式。need 情態(tài)動詞 實(shí)義動詞現(xiàn)在時You need (not) do He need (not) do You (dont) need to do He needs (doesnt need) to do 過去時You needed (didnt need) to do He needed (didnt need) to do將來時You need (not) do He need (not) do You will

21、(not) need to doHe will (not) need to dodare 情態(tài)動詞 實(shí)義動詞現(xiàn)在時 dare to/darent/dare not doDare he do? dare/dares to dodo/does not dare (to) doDo you/Does he dear (to) do?過去時dared to/dared not doDared he do? dared to do/did not dare (to) doDid he dare (to) do1) 用作情態(tài)動詞。例如：|You neednt telephone him now. She

22、dare not go out alone at night. 她晚上不敢一個人出去。2) 用作實(shí)義動詞。例如：You dont need to do it yourself. I dare say hell come again.我想他會再來（I dare say為固定二、 情態(tài)動詞表推測：1.can 表示可能（理論上或是邏輯判斷上）。例如：,_K He cant (couldnt) have enough money for a new car. 他不可能有足夠的錢買新車。 You mustnt smoke while youre walking around in the wood. Y

23、ou could start a fire. 在林子里走時勿吸煙，那樣可能會引起火災(zāi)。2.may 表可能（事實(shí)上）?？梢灾高^去時間，也可以指現(xiàn)在時間，但語氣更加不肯定。 He may be at home. 他可能在家。 She may not know about it.3. must 表示揣測。意為“想必、準(zhǔn)是、一定”等，只用于肯定句。 He must be ill. He looks so pale. 他準(zhǔn)是病了。他的臉色蒼白。 Shes wearing a diamond necklace. She must have a lot of money. 4. should 表推測，意為“

24、想必一定、照說應(yīng)該、估計(jì)”等。例如： The film should be very good as it is starring first-class actors. 這部新電影是一流演員主演的，估計(jì)拍得很好。 They should be home by now. 照說他們現(xiàn)在應(yīng)當(dāng)已經(jīng)到家了。5. ought to 表推測，暗含很大的可能，語氣較弱。例如： Han Mei ought to know his telephone number. 韓梅該知道他的電話號碼。 Theres a fine sunset; it ought to be a fine day tomorrow. 今天

25、有晚霞，明天應(yīng)該是個好天。6. could可能性不大，語氣較弱。7 might 可能性最小，語氣最弱。表示可能性大小的順序?yàn)椋?must will would ought to should can could may might7.would rather, would sooner, would (just) as soon, had rather, had better, had sooner, can not but, may (just) as well等可用作情態(tài)動詞。例如：1）The soldier would sooner die than surrender. The bra

26、ve soldier would as soon die as yield to such an enemy. Id rather walk than take a bus.If you dont like to swim, you may just as well stay at home.2)would (had) rather, would (had) sooner, would (just) as soon后可跟that 引導(dǎo)的從句，that 常省去，從句要用虛擬語氣。對現(xiàn)在和將來的假設(shè)用過去時，對過去的假設(shè)用過去完成時。例如：I would rather you came on Su

27、nday. I would sooner you hadnt asked me to speak yesterday.8.表推測的情態(tài)動詞句子的反意疑問句He must/may be in the room, isnt he? He cant be in the room, is he？He must have finished the work, hasnt he? He may have done the work last night, didnt he?結(jié)構(gòu)：1情態(tài)動詞+ 動詞原形 （對現(xiàn)在和將來的動作進(jìn)行推測）He must understand that we mean busin

28、ess.2情態(tài)動詞+ be +doing (對正在發(fā)生的動作進(jìn)行推測)-Where is LiLei ? - He may be studying at school.3.情態(tài)動詞+ have +done ( 對過去的動作進(jìn)行推測) must have done 一定干了某事 could have done 可能干了某是或本可以干了某事may/might have done 也許已經(jīng)干了某事 should/ ought to have done 本應(yīng)該做了某事可是沒有做need not have done 本不必干了某事 表示過去做了某事，但沒有做的必要，意為“本沒必要” You neednt

29、 have waken me up; I dont have to go to work todayhad better have done 最好干了某事 would rather have done 寧愿干了某事would like / love have done 本想干了某事其實(shí)未干 Since the road is wet, it must have rained last night.備注：態(tài)動詞 + have +done 反義問句的結(jié)構(gòu)由有無時間狀語來決定。Lucy must have worked last night, didnt she?Lucy must have wor

30、ked , hasnt she? 4.情態(tài)動詞+ have been + v-ing形式 （表示推測或評論過去某動作是否正在進(jìn)行或一直在進(jìn)行）They should have been meeting to discuss the problem.三、情態(tài)動詞其它用法1. cannot but do sth. 表示不得不，只好 I cannot but choose to go.2. may well +動詞原形 完全能， 很可能 He may well be proud of his son.3. may as well 最好 We may as well stay where we are

31、.4 cannot ( 或never 等否定詞)與enough 表示再也不為過 You cannot be careful enough.情態(tài)動詞練習(xí)題1. Jack described his father, who _a brave boy many years ago, as a strongwilled manA. would be B. would have been C. must be D. must have been 2.You_ buy a gift, but you can if you want to.A. must B. mustnt C. have to D. do

32、nt have to3. I have told you the truth. _ I keep repeating it?A Must B Can C May D Will4. I_ have watched that movie itll give me horrible dreams. A. shouldnt B. neednt C. couldnt D. mustnt5. Mark _ have hurried. After driving at top speed, he arrived half an hour early.A. neednt B. wouldnt C. mustn

33、t D. couldnt 6. _ I take the book out? Im afraid not.A. Will B. May C. Must D. Need7.Just be patient .You _ expect the world to change so soon .A. cant B. neednt C. may not D. whether 8.I havent got the reference book yet, but Ill have a test on the subject next month. Dont worry. You_ have it by Fr

34、iday.A. could B. shall C. must D. may 9.May I take this book out of the reading room? No, you_ . You read it in here. A. mightnt B. wont C. neednt D. mustnt10.Doctors say that exercise is important for health, but it _ be regular exercise.Acan Bwill Cmust Dmay11.-Good morning. Ive got an appointment

35、 with Miss Smith in the Personnel Department. -Ah, good morning. You _ be Mrs. Peters. A. might B. must C. would D. Can12.“You _ have a wrong number,” she said. “Theres no one of that name here.”A. need B. can C. must D. would 13.-Sorry, Professor Smith. I didnt finish the assignment yesterday.-Oh,

36、you _ have done it as yesterday was the deadline.A. must B. mustnt C. should D. shouldnt14. Bob would have helped us yesterday, but he-_A. was busy B. is busy C. had been busy. D. will be busy 15. John went to the hospital alone. If he_ me about it, I would have gone with him.A. should tell B. tells

37、 C. told D. had told 16. George is going to talk about the geography of his country, but Id rather he_ more on its culture.A. focus B. focused C. would focus D. had focused17.If we _ the other road, we might have arrived here in time for the meeting. A. take B. had taken C. took D. have taken18.-The

38、 weather has been very hot and dry. -Yes. If it had rained even a drop, things would be much better now! And my vegetables .A. wouldnt die B. didnt die C. hadnt died D. wouldnt have died 19Had I known about this computer program, a huge amount of time and energy . Awould have been saved Bhad been sa

39、ved C.will be saved Dwas saved20. Its the office! So you_ know eating is not allowed here. Oh, sorry.A. must B. will C. may D. need21. What do you mean, there are only ten tickets? There_ be twelve.A. should B. would C. will D. shall22. I dont care what people think. Well, you _A. could B. would C.

40、should D. might23.I cant find my purse anywhere.You have lost it while shopping.A.may B.can C.should D.would24.It is usually warm in my hometown in March，but it be rather cold sometimes.A.must B.can C.should D.would25.Hows your tour around the North Lake? Is it beautiful?It_ be， but it is now heavil

41、y polluted.A.will B.would C.should D.must26.Whats the name?Khulaifi. _ I spell that for you?A.Shall B.Would C.Can D.Might27.John，look at the time. _ you play the piano at such a late hour?A.Must B.Can C.May D.Need28.Catherine，I have cleaned the room for you.Thanks. You_ it.I could manage it myself.A

42、. neednt do B. neednt have done C.mustnt do D.shouldnt have done29.Ill tell Mary about her new job tomorrow.You_ her last week.A.ought to tell B.would have told C.must tell D.should have told30.Excuse me.Is this the right way to the Summer Palace?Sorry，I am not sure. But it_ be.A.might B.will C.must

43、 D.can1. D. 考查情態(tài)動詞推測用法。句意為“杰克把他的父親描述為一個意志堅(jiān)強(qiáng)的人，他的父親多年前肯定很勇敢?！庇胢ust have been表示對過去事情的肯定推測。2. D情態(tài)動詞dont have to 意為“沒有必要”，符合語境，句意為：“你沒有必要買禮物，但如果你想買的話，你也可以買。”3. A考察情態(tài)動詞的用法。must 必須, 一定 can 可以, 能夠 may 也許 will 意愿, 傾向性動作, 前半句說我告訴你事實(shí)了, 這里用的是現(xiàn)在完成時, 表示過去的動作對現(xiàn)在造成了影響, 既然我已經(jīng)說了, 我還必須重復(fù)一遍嗎？4.A本題考查情態(tài)動詞的用法。句意應(yīng)為“我本來不應(yīng)該

44、看那部電影的-它會使我做噩夢的?！北硎尽氨緛聿粦?yīng)該做而做了某事”用shouldnt have done, 所以A項(xiàng)正確。5. A. 考查情態(tài)動詞。邁克本來不必要那么忙的。這么高速駕駛之后，他早半個小時到達(dá)了。根據(jù)后面的語境，提前半個小時到達(dá)，說明Mark本來不必那么匆忙，所以用neednt have done 結(jié)構(gòu)，表示“本來不必要做某事的而實(shí)際上做了”。6.B考查情態(tài)動詞。表請求可用情態(tài)動詞can, may, could, might ,表允許用can, may.句意為：“我可以將這本書帶出去嗎？”“恐怕不行”。故應(yīng)選表情請求的情態(tài)動詞may。7. A耐心一點(diǎn)兒，你不能期望世界變化如此快。通

45、過選項(xiàng)此題考察情態(tài)動詞，cant在否定句中可以表示推測，譯為不可能，可以表示能力，譯為不能夠，也可以表示命令，不允許，但是語氣比mustnt弱，具有勸慰的意思，根據(jù)句意此題中選擇A，cant表示勸慰。8. B，shall在第二人稱中表示允諾，還可以表示強(qiáng)制，命令，威脅，警告。還有在法律條文中的要求或規(guī)定。9. D情態(tài)動詞。英語中用could，might表示詢問或征求意見的問句中，肯定性應(yīng)答要用can或may來代替could或might，而may或might征求意見的問句否定應(yīng)答時要用mustnt，故本題選D。10C句意：醫(yī)生說鍛煉對身體重要，但是必須是有規(guī)律的鍛煉?？疾榍閼B(tài)動詞。Can一般表示“可能，或能力”；will表示“意志”；may表示“許可，可能”；must表示“必須”。11. B本題考查情態(tài)動詞在語境中的運(yùn)