高三英語：專題十情態(tài)動詞與虛擬語氣一

1、2011年高考英語二輪專題復習專題十 情態(tài)動詞與虛擬語氣（一）考點分析情態(tài)動詞1.考查情態(tài)動詞的基本用法shall用于一、三人稱疑問句表示征求對方意見；用于二、三人稱陳述句表示說話人給對方的命令、警告、允諾或威脅等；may表示“允許、可以”，語氣比較委婉。must用于疑問句，表示責備、抱怨的感情色彩，意思為“偏偏，偏要”，mustnt表示禁止，是說話人強有力的勸告。cannot 表示“不可能”；need not 表示“不必要”；may not 表示“可能不，可以不”。neednt表示“沒有必要”would表示過去反復發(fā)生的動作或某種傾向表示經過努力而成功的某一次動作，只能用was/were a

2、ble to,而不能用could；could還可以表示過去的某種能力考查情態(tài)動詞用作答語的情況2.考查情態(tài)動詞+動詞不定式一般式表推測的用法肯定的推測一般用must,should,may(might)或could(不用can)，其中，must的語氣最強，譯為“肯定”、should的語氣次之，譯為“很可能”、“應該”；按常理推測的may(might),could語氣最弱，譯為“也許”。否定的推測：語氣不很肯定時，常用may not,might not或could not，譯為“可能不”“也許不”；否定語氣較強時，則用cant，譯為“根本不可能”、“想必不會”，表示驚異、懷疑的感情色彩疑問句中推測

3、往往用can或could3.考查情態(tài)動詞+動詞不定式的完成式表推測的用法4.考查情態(tài)動詞+動詞不定式完成式的其他用法should(ought to)+不定式的完成式：本來應該做而實際上又沒有做。其否定形式表示某中行為不該發(fā)生卻發(fā)生了。neednt+不定式的完成式：本來不必要做的而實際上又做了could+不定式的完成式：本可以做而實際上未能做,含有遺憾的意味虛擬語氣1.虛擬條件句的基本結構及其用法 與現(xiàn)在事實相反的虛擬條件句 與過去事實相反的虛擬條件句 與將來事實相反的虛擬條件句2.虛擬語氣的活用 時間錯綜虛擬結構 省略if的虛擬結構 并列連詞或副詞暗示的虛擬結構 介詞或介詞短語暗示的虛擬結構

4、as if / as though方式狀語從句中的虛擬語氣 名詞性從句中的虛擬語氣 分詞短語暗示的虛擬結構上下文語境中的虛擬結構 知識點歸納I.情態(tài)動詞1.表示“能力、許可”的can /may表示能力的情態(tài)動詞用can/could A computer_think for itself, it must be told what to do. A.cant B.couldnt C.may not D.might not表示許可時用may/might ,can/could 都可以，但在問句中用could? 或might？ 以使口氣委婉客氣，其回答一定要用can或may，以使回答口氣明確（must

5、表示一定，必須，mustnt表示禁止，不許可）Could I call you by your first name? Yes, you_. A.will B.could C.may D.mightJohnny, you_play with the knife, you_hurt yourself.A.wont/cant B.mustnt/may C.shouldnt/must D.cant/shouldnt在肯定句中could不可以用來表示過去某一特定場合的能力，而要用was/were able to。如不可以說：They could jump into the sea before the

6、 boat was blown up而要說：they were able to/managed to jump intoThe fire spread through the hotel very quickly but everyone_get out.A.had to B.would C.could D.was able to但在否定句中could/was(were)able to可以通用:I couldnt/wasnt able to see him yeaterday.表示許可時用may/can都可以。只不過用may時較側重講話人的許可，而can較側重客觀情況的許可，must則表示必須

7、做某事。2.表示“推斷、判斷”的can,may,must在肯定句中都可以用來表示可能。在含義上must語氣最為肯定,may表示的是事實上的可能性：Peter_come with us tonight, but he isnt very sure yet. A.must B.may C.can D.will而can表示的是邏輯上的可能性：Mary is in poor health. She can be ill at any times.在否定句中只能用can和may。此時cant用以代替mustnt，語氣比may not更強。cant中文可以翻譯為“不可能”、may not中文可以翻譯為“可

8、能不”。Michael_be a policeman, for hes much too short. A.neednt B.cant C.should D.may在疑問句只能用can，不能用may和mustHe may be very busy now. Can he be very busy now?He must be very busy now. Can he be very busy now?3.表示“請求、提議”（用在疑問句中）的can和could，這時could比can語氣更婉轉Can（Could）you give me a lift to the station?你（您）能不能

9、讓我搭你（您）的車去車站呀？4.表示“驚訝、懷疑”（用在疑問句中）的can和could，這時could比can語氣更婉轉Who can it be at this time of day?這個時候到底會是誰呢？5.構成下列特殊句式的cancan not/can nevertoo cannotenough“無論怎么也不為過分，越越好，非?！盨ince it is a good thing,we cannot do it too soon. 既然是好事情，我們越早開始做越好。cant help doing,cannot help but do,cannot but do“禁不住，不由得，不得不”I

10、 cannot help admiring the picture whenever I look at it.每當我看到這幅畫時，我都禁不住要鑒賞它。When a close friend dies,you cannot but feel sad. 親密的朋友去世時，你會不由得感到悲傷。6.表示祝愿、祝福的may,此時句子用倒裝語序 May he live to an old age!愿他長命百歲！ May God be with you!愿上帝保佑你！7.shall/should用于人稱意義shall第一、三人稱征求對方的意見第二、三人稱說話人給對方的警告、命令、允諾、威脅用于法律、法規(guī)等

11、條文中應，須，得What shall we do this evening?注意：may用于征求對方的許可，而shall用于征求對方的意見或指示：May I have a look?我能看一看嗎？Shall I have a look?需要我看一看嗎？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）e.g.The fine shall be given in cash.罰款須以現(xiàn)金繳納。should 意義

12、（表義務、責任的）應該（表預期的）應該會，想必會，一定會把（表驚訝、遺憾的）竟然、居然（與疑問詞連用，表意外、驚訝、納悶等的）究竟是，到底（用于表示命令、建議、請求等詞后面的that從句中，且should可以省略）應該，必須You should apologize to him.The photos should be ready by 12:00.Im surprised that you should speak in such a way.Who should ccome in but my old friend Betty.我當究竟是誰進來了呢，原來是我的老朋友貝蒂呀。I sugges

13、ted that he (should)change his mind.My suggestion was that he (should)change his mind.注意：ought to表示 “應該” (與should同義, 只是語氣稍重一些), 也可表示推測。You ought to take care of him. He ought to be home by now.8.will/would請求、建議，would比will委婉客氣Would you pass me the book?表示意志、愿望和決心I will never do that again.They asked

14、us if we would do that again可表示過去反復發(fā)生的動作或某種傾向During the vacation he would visit me every weekThe wound would not heal.表示估計或猜想It would be about ten when he left home.What would she be doing there?9.dare和needneed作為情態(tài)動詞只有一種形式，只用于否定句和疑問句。dare作為情態(tài)動詞用時有兩中形式：dare和dared兩個詞形。除了可以用于否定句和疑問句外，還可以用于條件從句或表示懷疑的句子中

15、。If he dare come,I will kick him out.I dont know whether he dare say.Note:He doesnt dare(to)answer the question.Does she dare(to)enter the dark room?10.情態(tài)動詞+have done的用法could+have done：本可以做而實際上未能做You could have done better, but you didnt try your best.cannot+have done：表示對過去行為的否定推測He cannot have been

16、 to that town.can+主語+have done：表示對過去行為的懷疑或不肯定Can he have got the book?might(may)+ have done：對過去發(fā)生的行為不太肯定的推測He may not have finished the work.If we had taken the other road, we might have arrived earlier.(Mood:mightmay,possibility:mightmay)must+have done：對過去發(fā)生的行為肯定的推測。其否定式為：cannot have doneYou must h

17、ave seen the film.You cannot have seen the film.neednt+have done：本來不必要做的而實際上又做了You neednt have watered the flowers,for it is going to rain.注意：didnt need to(have to)do :沒有必要做而實際上也沒有做I didnt need to clean the windows.My sister did it 2 hours ago.should(ought to)+ have done：本來應該做而實際上又沒有做。其否定形式表示某種行為不該發(fā)

18、生卻發(fā)生了。You should have started earlier, but you didnt.She shouldnt have taken away my measuring tape, for I wanted to use it.注意：本結構還可以表“推測”的意思He should have finished the work by now. 到現(xiàn)在他應該已經做完那項工作了。11.其它情態(tài)動詞have tohave to表示 “必須, 不得不”, 在這個意義上與must很接近, 但must表示的是說話人的主觀看法, 而have to表示的卻是客觀需要. have to比mus

19、t有更多的形式。The TV set is broken. I have to buy a new one.The students will have to know how to use the computers.注意：在回答must的問句時, 否定式常用need not(neednt)或dont have to表示 “不必”。而不用must not, 因為must not表示 “不可以”。used to表示過去的習慣動作或狀態(tài)(現(xiàn)在已不復如此)Did you use to go there to see your brother? /Used you to go there to se

20、e your brother?Yes, I did(used to). /No , I didnt (usednt).注意：would也可表示過去反復發(fā)生的動作或某種傾向，但是不涉及到現(xiàn)在。had better表示 “最好(做)”We had better go now. 其否定式為had better notII.虛擬語氣（一）一般虛擬結構 類別用法例句If引導的條件從句與現(xiàn)在事實相反從句動詞：過去式（be用were）主句動詞：should/would/could/might+動詞原形If he were here, he would help us.與過去事實相反從句動詞：had+過去分詞

21、主句動詞：should/would/could/might+have+過去分詞If I had been free, I would have visited you.與將來事實相反從句動詞：過去式 / should+動詞原形 / were+不定式主句動詞：should/would/could/might+動詞原形If it should rain tomorrow, we would not go camping.注意:主句中的should只用于I、we，但在美國英語中，should常被would代替；從句中的should可用于各種人稱，且不可以被would所代替。（二）混合虛擬結構（錯綜時

22、間條件句）有時在非真實條件句中，主句謂語動詞所表示的動作和條件從句中謂語動詞所表示的動作并不同時發(fā)生，這時主句和從句的謂語動詞要根據(jù)各自所指的不同時間選用適當?shù)奶摂M語氣形式。如：Had I taken my umbrella with me when I came out this morning, I should not be wet now.如果我今天早上出來的時候帶著傘的話，現(xiàn)在就不會淋濕了。（從句說的是過去的事情，而主句說的是現(xiàn)在的事情）If you had followed the doctors advice, you would be all right now.如果你（那時）

23、聽從我的建議的話，現(xiàn)在就不會有事了。（從句說的是過去的事情，而主句說的是現(xiàn)在的事情）If I hadnt finished my composition by now, I would be working on it tomorrow.如果到現(xiàn)在為止我還沒有完成作文的話，我明天還要接著寫。（從句說的是現(xiàn)在的事情，而主句說的是將來的事情）（三）特殊句式虛擬結構1.省略連詞if。在書面語中，如果虛擬條件從句中有were，had 或 should，可以把if省略，把這幾個詞放到主語之前，構成主謂倒裝。Should he come (If he should come), tell him to r

24、ing me up. 他要是來了，讓他給我打個電話。Were I you (If I were you), I would not do it. 我要是你，就不做這事。2.suggest, order, propose, request, require, demand, advise, insist+ 賓語從句(should )doHe suggested that we (should) save money for the future.The undergraduate insisted that he (should) go to work in the south.注意：當sugg

25、est表示暗示，insist表示堅持觀點,事實時，后接的賓語從句應當用真實語氣。His silence suggested that he agreed with my decision.He insists that doing morning exercises does good to peoples health.3.It is suggested/advised/ordered/requested/required+ that從句(should) doIt is proposed that more students should go to university.4.My advi

26、ce/suggestion/request/requirement/order/proposal+ is +表語從句(should)do My advice is that you should practise speaking English as often as possible.The order from the commander was that the troops should set off for the front immediately.5.His suggestion/advice/request/requirement+ 同位語從句(should )do+ is

27、. The request that they should get more is reasonable.6.It is natural/necessary/strange +that從句 (should) do表驚奇、懷疑、惋惜、不滿、理應如此等。Its strange that he should have missed the train. （表竟然） It is important that we should learn from others.（表理應如此）It is a pity that he should not go with us.(表驚訝、不滿)7.wish + th

28、at clause (did/were 與現(xiàn)在相反)wish + that clause (would/could/might + do與將來相反)wish + that clause ( had done 與過去相反)I wish I could go with them tomorrow. I wish I had never met him.8.It is (high/about) time + 從句(did或should do )It is (high/about) time we went home.9.would rather + clause (did 與現(xiàn)在或將來相反)；（ha

29、d done 與過去相反）I would rather you came tomorrow.I would rather you hadnt told her the news.10.省去條件從句或主句：表示虛擬語氣的主句或從句有時可以省略，但其含義仍可以推知。省去條件從句You could have washed your clothes yourself. 你本可以自已洗衣服的。省去了If you had wanted to)(事實是:你自己沒洗衣服，因為你不想洗。)省去主句(常用以表示愿望) If only + clause ( did/were與現(xiàn)在相反)/ (would/could/

30、might + do與將來相反) /( had done 與過去相反) “要是.就好了“ If my grandmother were with me! 如果我的祖母與我在一起多好啊!(事實是:祖母已不在世。)If only she had not left! 如果她沒走就好了!(事實是:她已經走了。)If only he would come tomorrow!If only I had taken her advice!If only I were ten years younger!注意：only if是“只要”的意思，從句中用陳述語氣。11.as if + clause (did/we

31、re 與現(xiàn)在相反) / (would/could/might + do與將來相反)/( had done 與過去相反) She treats Kate as if she were her own daughter. They talked as if they had been friends for years.12.would like/was/were to have done somethingI would like to have attended the party, but one of my friends came to see me.13. 用with, without

32、，but for等介詞短語來替代條件從句, 它們都可以轉換成由if引導的虛擬條件句。如：We might have died without your help. =We might have died if you hadnt helped us.如果（那時）沒有你們的幫助，我們可能已經死了。Without the sun, nothing would grow. = If there was no the sun, nothing would grow.沒有太陽，萬物都不能生長。14. 用or, otherwise, but that, suppose/ supposing (that),

33、 provided / providing (that) 等引導的虛擬語氣。如：You didnt come yesterday, or you would have seen him.你昨天沒有來，否則的話，你就已經看到他了。I was very busy last week, otherwise I would have come to see you. 我上周很忙，否則的話，我就來看你了。Supposing I was still a little child, I would study hard from now on. 假如我還是一個小孩子的話，我將從現(xiàn)在開始努力學習。15由sho

34、uld +動詞原形或者should/could/might have +過去分詞構成的虛擬語氣。有種情況下，虛擬條件句經常省略，而只剩下主句結構，如：I should have told you that, but I was afraid that you couldnt accept the fact.我本應該告訴你那件事，但我擔心你不能接受這個事實。Tom, you are so lazy! This work should have been finished hours ago.湯姆，你太懶了！這個工作本應該幾個小時之前完成。16在if it were/had been not fo

35、r 句型中的虛擬語氣If it were not for,表示對現(xiàn)在事實的假設；If it had not been for,表示對過去事實的假設。If it were not for the Internet, everything would be very difficult. 要不是互聯(lián)網(wǎng)，一切都會變得很難。Had it not been for your overcoat, I would have died. 要不是你那件大衣，我就被凍死了。17.注意轉折語氣連詞引導的虛擬語氣He hesitated for a moment before kicking the ball, ot

36、herwise he would have scored a goal.I told Sally how to get here, but perhaps I should have written it down for her.The captain kept calm in the terrible storm, otherwise the accident wouldnt have been prevented.Yesterday, Jane walked away from the discussion. Otherwise, she might have said somethin

37、g she would regret later.18.注意分詞和獨立結構引導的虛擬語氣Given more than two hours, we could have done the work better.Not having finished the work, he couldnt have seen this film. 高考預測1. Why didnt you tell me there was no meeting today? I _ all the way here _the heavy snow. A. neednt have driven；through B. cant

38、 have driven；acrossC. mustnt have driven；through D. shouldnt have driven；cross 2. Mum, its none of my business. Why _ I care? Just because she is your sister. A. can B. should C. will D. may3. I didnt know you were good friends .You_.I have known her since she moved here. You were studying abroad th

39、en.A.may have B.neednt have C.couldnt have D.must have4. The concert was wonderful! Really? How I wish I _to the theatre with you yesterday!A. had gone B. might go C. were able to go D. would go5.The two strangers have been talking in the park for a long time as though they _old friends.A. are B. sh

40、ould be C. were D. would be6. _the heavy rain, we _the town.A. But for; should have reached B. Because of; would have reachedC. During the period of; we would reach D. In spite of; we should have reached7. If William _, he _that green peach. Luckily he was sent to the hospital in time.A. was warned;

41、 would not take B. had been warned; would not have takenC. would be warned; had not taken D. would have been warned; had not taken8. Is it good to look up every new word when I come across it in reading?No. You _because you are likely to guess the meaning from the context.A. cant B. mustnt C. dont h

42、ave to D.ought not to9. _I use your computer to send an e-mail?Yes, you _. But you mustnt keep it too long.Ill surf the Internet after supper.A. Could; could B. Could; must C. Can; can D. Could; can10. When he lived there, he _go to that book shop at the corner with his girlfriend after work every d

43、ay.A. would B. should C. had better D. might11. I hear youve got a set of Australian coins. _I have a look? Yes, certainly.A. Do B. May C.Shall D. Should12. What happened to the young trees we planted last week? The trees_well, but I didnt water them.A. might grow B. neednt have grown C. would grow

44、D. would have grown13. What _ had Bob walked farther, as far as the river bank?A. would happen B.could happen C. would have happened D.neednt have happened14. Hurry up,Tom.Its high time we_ to the theater.A. will B. shall C. are going to D. went15. Do you think he will do me a favor? As far as I kno

45、w, he is the last one to help others. He_be prepared to give you a hand, though.A. might B. must C. can D. should16. Even though Id hurt my leg, I_swim back to the river bank.A. could B. might C. had to D. was able to17. It is rather cold here. Shall we light a fire? No, we_because things are easy t

46、o catch fire.A. wont B. cant C. mustnt D. neednt18.Would you have told him the answer had it been possible? I would have, but I _so busy then.A. had been B. were C. was D. would be19. The young man insisted that he_ these watches and_free.A. stole, set B. had stolen, be set C. steal, be set D. had s

47、tolen； must be set20. I _your address, otherwise I_you long before.A. had forgotten,had visited B.forgot, have visited C. forgot,would have visited D.have forgotten,would visit21. I_you a beautiful present for your birthday,but I was short of money at that time.A. would buy B. had bought C. would li

48、ke to have bought D. must have bought22.Do you feel like _ there or shall we take a bus? Id like to walk. But since there isnt much time left, Id rather we_ a taxi. A. walking,hire B. to walk, hire C. to walk,hired D. walking, hired23. Miss White has decided to explore in the forest by herself.She_a

49、sk her boyfriend to if she _go walking in the forest.A.neednt to,dares to http:/ B.doesnt need, dares C.need not to,dare to D.neednt, dare24. His failure in the exam suggested that he _ the teachers instructions.A. cant have followed httB. neednt have followed C. mustnt have followed D. shouldnt have followed25.I _ you, but I didnt think you would listen to me.A.could have told B.must have told C.should tell D.might rell26.Ms Li