常考点清单情态动词的用法要点.docx

常考点清单一 情态动词的用法要点一、表能力如：I am starving to deathI Can eat two bowls of rice now(现在的能力)我快饿死了，现在我能吃两碗米饭。If you have a good sleep，you will be able to work out this problem(将来的能力)如果你好好睡一觉，你将能够解出这道题。The fire spread through the hotel very quickly but everyone was able to get out(过去有能力做并且成功地做了某事)尽管这场大火迅速蔓延到了整个宾馆，但是每个人都逃了出去。I could have worked out the problem，but I was too nervous(过去有能力做但未做)我本来可以解决这个问题，但我太紧张了题组训练 单项填空：I should have been there, but I _ not catch the bus.A. would B. couldC. might D. should-I stayed at a hotel while in New York.-Oh, did you? You with Barbara.A. could have stayed B. could stayC. would stay D. must have stayed二、表推测(可能性)1可能性可分为客观的可能性和具体事情实际发生的可能性两种。所谓客观的(理论的)可能性即并不涉及具体某事是否会发生，此种用法常常可以说明人或事物的特征。情态动词can可用于肯定句中表示客观的(理论的)可能性，而表示具体事情实际发生的可能性时，can一般不用于肯定句。如：Accidents can happen on such rainy days这样的多雨天气可能会发生事故。(客观的可能性)We may go to the cinema tonight，but we are not sure yet今晚我们可能去看电影，但还没确定。(实际可能性，不用 can)2表示具体事情实际发生的可能性：(1)表示具体事情实际发生的可能性的层次比较(见下表)词形肯定式否定式疑问式must必定，必然/will很可能，大概不会，不该会吗?would可能性比will小语气比wont弱语气比will弱should按说应该/ought to按说应该/can/不可能有可能吗?could微弱的可能不可能语气比can弱may或许，也许，也未可知，也说不定可能不/might比may还弱比may not还弱/(2)表示具体事情实际发生的可能性时，may，must常用于肯定句，一般不用于否定句和疑问句(may not表示“可能不”)；can常用于否定句、疑问句或感叹句中，表示疑惑、惊讶或不相信等意思；could既可用于肯定句又可用于否定句、疑问句中。如：This cant/couldnt be done by him这不可能是他干的。(表不相信)This may not be done by him这可能不是他干的。(表不确定)He could be on his way home now。他现在可能在回家的路上了。(could不如may/might常用)Can this be done by him?这可能是他干的吗?(表示疑惑、惊讶)Mr. Bush is on time for everythingHow can it be that he was late for the opening ceremony?布什先生做一切事情都非常守时。开幕式他怎么可能会迟到呢?(表示疑惑、惊讶)I didnt hear the phoneI must have been asleep我没听见电话铃响。我一定是睡着了。(表肯定)-Are you coming to Jeffs party?你要来杰夫的聚会吗?-Im not sureI might so to the concert instead(表不确定)我不确定。我可能要去音乐会。题组训练 用can，could，may，might填空：-Is John coming by train?-He should, but he _ not. He likes driving his car.Peter come with us tonight, but he isnt sure yet.Sorry Im late. I _ have turned off the alarm clock and gone back to sleep again.That _ not be Mary. Shes in hospital.How _ you be so stupid?(3)would，could，should，might并不一定与过去时间有关，而表示可能性弱于它们相应的现在时形式。如：This may/might be done by him这件事有可能是他干的。(语气依次递减)(4)should表推测时，表示确定或可能有的未来或期望，即合乎理想的情况或结果。如：He ought to/should be here on time-he started early enough他(应)该按时到这里他出发得够早的了。We should arrive before dark我们按说能在天黑前到达。The roads should be less crowded today按说今天路上就不那么拥挤了。三、表示请求、允许、允诺1当对方是决策者时，你代表你(们)自己(I，we)，或代表第三者(he，she，they)向对方(you)请示或提出建议时用： Shall/May(Might)/Can(Could)/we? Shall he/she/ they ? Would/Will you?如：Shall the driver wait outside?司机在外边等着可以吗?When shall my father be able to leave hospital?我父亲什么时候可以出院?Would you do me a favor?请帮我一下，好吗?2could/might/would/should表委婉的语气。如：-Could/Might I use your bike tomorrow morning?-Yes，you can/may(否定：No，Im afraid not)明天早晨我用用你的自行车，行吗?行，你用吧。(否定：不，恐怕不行。)不可说：Yes，you could/might回答允许时，用could/might表委婉是不恰当的。题组训练 单项填空：-The room is so dirty, _ we clean it?-OK.A. Will B. ShallC. Would D. Do- _ he come to see you?-Of course, please. And Id rather he told me the truth.A. Will B. ShallC. Would D. Do3shall还可以表命令、警告、威胁；宣布法律、规定时，也要用shall。如：You shall leave the room at once, and he also shall. (=I order you and him to leave the room at once.)你马上滚出这个房间，他也一样。(说话者的意志)It has been anannounced that candidates shall remain in their seats until all the papers have been collected已宣布，在所有试卷收上来之前，应试者必须留在自己的座位上。(规则或规定)题组训练 单项填空：He asked me for this book many times. Please tell him he _ have it tomorrow.A. must B. mayC. shall D. both B and CIt has been announced that all the students _ put on masks(口罩) before going to school in case they are infected with SARS virus.A. shall B. willC. need D. may四、表示必要性1must常用来表示必要性，意为“必须”：(1)must + do sth. (现在或将来)必须做某事(2)dont have to do sth./ dont need to do sth./ neednt do sth. (现在或将来)不必做某事 (3)表示过去没必要做某事时，分为以下情况：neednt have done sth. 本来不必做而做了某事didnt have to do sth./ didnt need to do sth./ It was not necessary to do sth. (过去)不必做(不强调是否做了)某事You neednt have worked that late last nightIt was harmful to your heath。你昨晚不必工作到那么晚。那对你的身体没好处。-Did you work very late last night?-NoI didntI didnt need to work very late你昨天晚上工作到很晚了吗?不是很晚。我没必要工作到很晚。2should也可以表示必要性，意为“(义务上)应该”。should表示必要性时，在语气上比must(必须)弱。“should+动词原形”表示现在或将来应该做(的必要性)；“should + have +过去分词”表示过去本该做(的必要性)。如：I should go and visit him this afternoonbut I wonder if I will be free今天下午我应该去看望他，但我不知道我是否有空。(表示将来的必要性)You should have come to the conference yesterday. What was the reason for your absence?你昨天应该参加那个会议。你缺席的原因是什么?(表示过去的必要性)题组训练 完成句子：You _ (没必要告诉)her the Hews，for I had told her about it earlier。I _ (没必要非得出去)but I wanted a breath of fresh airWe _ (本该买)a new lock for the front door五、表示“宁愿做某事”时可使用下面这些句式：would rather do sth.would rather do sth. than do sth.would do sth. rather than do sth.would rather sb. did sth.prefer to do sth.prefer to do sth. rather than do sth.prefer doing sth. to doing sth.高考中对这类用法的考查主要侧重结构，因此要熟记其结构。六、“情态动词+have done”用法一览表情态动词+完成式用法例句must have done想必/准是/一定做了否定式为：cant/couldnt + have doneIt must have rained last night for the road is quite muddy昨晚一定下雨了，因为路很泥泞。can/could have done1本来能够做2过去可能会做Can he have gone to his aunts?他有可能去他姨妈家了吗?cannot/could not have done1过去不可能2过去没能够He cannot have forgotten it他不可能忘了那件事。may/might have done也许/或许已经做，一般只用于肯定句或否定句中(在否定句中表示“可能不”)，不用于疑问句。用might则表示语气更加不肯定。Its too late，I think he may have gone to bed太晚了，我想他或许已经睡了。He may not have finished the work他也许还没完成那项工作。should/ought to have done本该做，而实际上未倣You ought to have done this exercise more carefully你本应该更仔细地做这个练习。should not/ought not to have done本不该做而做了You shouldnt have told her the truth你本不该告诉她真相。neednt have done本不必做而做了You neednt have taken a taxi here，for it Was very near to my house你本来不必打车来这里的，因为这里离我家很近。had better have done当时最好做了(其否定式had better not have done表达相反的含义)You had better not have scolded her要是那时你没责骂她就好了。would rather have done宁愿当时做了(其否定式would rather not have done表达相反含义，两者都表示“后悔”之意)I raised objections at the meeting，but now I would rather not have done that我在会上提出了反对意见，但我现在宁愿没那么做。would like/love to have done sth过去愿意做但未做成I would love to have gone to the party last night, but I had to work extra hours to finish a report昨晚我本来很想去参加聚会的，但我得加班完成一个报告。题组训练 单项填空：I told Sally how to get here, but perhaps I _ for her.A. had to write it outB. must have written it outC. should have written it outD. ought to write it outI was really anxious about you. You _ home without a word.A. mustnt leave B. shouldnt have leftC. couldnt have left D. neednt leaveHe hesitated for a moment before kicking the ball, otherwise he _ a goal.A. had scored B. scoredC. would More D. would have scored七、情态动词其他用法要点：1cannot but + do sth表示“不得不，只好做某事”。如：I cannot but choose to go我只好去。2may well和may as well结构。“may well+动词原形”是一种常用结构，意为“完全能，很可能”，相当于to be very likely to。如：He may well be proud of his son他大可为他的儿子感到自豪。Her appearance has changed so much that you may well not recognize her她的模样变化太大，你很可能认不出她了。“may as well+动词原形”意为“最好，满可以，倒不如”。如：You may as well do it at once你最好马上就做这件事。We may as well stay where we are. 我们留在现在的地方倒也不错。3cannot(或never等否定词)与enough连用表示“再也不为过”。(具体用法见形容词和副词专题。)4may可以用于祈使句，表示祝愿。如：May we never forget each other愿我们彼此永不相忘。May you return in safety。愿你平安归来。5“Why/How + should”结构表示说话人对某事不能理解，感到意外、惊异等意思，意为“竟会”。如：Why should you be so late today? 你今天怎么来得这么晚?How should I know? 我怎么会知道?(意为：我不知道。)题组训练 翻译下列句子：我不得不钦佩你的勇气。(cannot but)_她很可能拒绝和你谈话。(may well)_你最好留在这里过夜。(may as well)_祝您的生活美满幸福。(may)_祝您成功!(may)_我真不明白你凭什么认为这件事是我干的。(should)_6must表示“偏要、硬要”。如：Must you make so much noise?你非得弄出这么大声响吗?If you must smoke，please go out如果你偏要吸烟，那你就出去吧。7may作“可以”讲时，其否定式常用“mustnt”表示“禁止” must作“必须”讲时，其否定式是“neednt”，表示“不必”。如：-May I use your car?-No，you mustnt我能用用你的车吗?不，一定不能。(委婉的拒绝可用：Sorry，but I am using it now或Youd better not等)-Must I work out the problem tonight?-No，you neednt我今晚必须做出这道题吗?不，不必。8need和dare的用法need和dare两者既可用作情态动词也可用作行为动词。作行为动词时，有人称和数的变化，可用于肯定句、否定句或疑问句中，构成否定句或疑问句时要用助动词do，does，did；作情态动词时，没有人称和数的变化(dare的过去式dared)，直接接动词原形，只用于否定句和疑问句中，构成否定句和疑问句时不用助动词。另外，dare作情态动词时，还可用于条件句中，过去式为 dared；作行为动词时，dare用于疑问句或否定句，后面的to也可省略；I dare say是习惯说法，意为“我想，大概”。如：He neednt do it(情态动词)He doesnt need to do it(行为动词)他不必做这件事。I didnt know whether he dared say that to him(情态动词，有时态变化)我不知道他是否敢对他说那话。He didnt dare(to)do it(行为动词)He dared not do it(情态动词)他不敢那么做。注意：need作行为动词时，还可表示“需要”，后接动名词的主动形式表示被动含义(详见“非谓语动词专题”)。如：The floor needs sweeping这地需要打扫了。题组训练 单项填空：Johnny, you _ play with the knife, you _ hurt yourself.A. wont; cant B. mustnt; mayC. shouldnt; must D. cant; shouldntHe _ go through the woods.A. dare not B. dares notC. dares not to D. not dare常考点清单一答案 B A may/might may/ might might can can B B D Aneednt have told didnt need/have to go out should have bought C B DI cannot but admire your braveryShe may well refuse to talk to youYou may as well stay here over the nightMay you have a happy lifeMay you succeed!I dont know why you should think(that)I did itB A常考点清单二 虚拟语气一、虚拟语气在非真实条件句中虚拟条件句主句与现在事实相反的假设If+主语+动词的过去式(be动词用were)主语 + should/would/could/might + 动词原形If I were you, I should seize the chance to go abroad.如果我是你，我就抓住这次出国的机会。与过去事实相反的假设If+主语+had+过去分词主语 + should/would/could/might + have + 过去分词If you had taken my advice, you would not have failed in the exams.如果你早听了我的意见，你考试就能通过了。与将来事实相反的假设1. If+主语+动词的过去式2. If+主语+were to+动词原形3. If+主语+should+动词原形主语 + should/would/could/might + 动词原形If he should not come tomorrow, we should put off the meeting tm next Monday.如果明天他不来，我们就把会议推迟到下周一了。使用虚拟条件句时要注意以下几点：1当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，被称为“错综时间条件句”，动词的形式要根据它所表示的时间做出相应的调整。如：If you had followed my advice just now，you would be better now如果你刚才听了我的建议，你现在就好多了。If you had studied hard before，you would be a college student now如果你以前好好学习的话，你现在早就是大学生了。2if省略句在条件句中可省略if，把were，had，should提到句首，变为倒装句式。如：If I were at school again, I would study harderWere I at school again, I would study harder如果我还有上学的机会，我会更加努力地学习。If you had come earlier，you would catch the busHad you come earlier, you would catch the bus如果你来得早些，你就能赶上公共汽车。If it should rain tomorrow，we would not go climbingShould it rain tomorrow，we would not go climbing如果明天下雨的话。我们就不去登山了。注意：若省略的条件句中的谓语动词是否定形式时，不能用动词的缩略形式。如：我们可以说：Were it not for the expense, I would go abroad now. 但不能说：Werent it for the expense, I would go abroad now. 3用介词短语代替条件状语从句。常用的介词有with，without，but for。如：What would you do with a million dollars (=if you had a million dollars)?如果你有100万美元，你会做什么?Without your help，we couldnt have finished the work ahead of time=But for your help，=If it had not been for your help，=Had it not been for your help，没有你的帮助，我们不可能提前完成这项工作。4含蓄条件句有时为了表达的需要，在虚拟语气中并不总是出现if引导的条件句，而是通过其他手段来代替条件句。如：I was ill that dayOtherwise, I would have taken part in the sports meeting(副词)我那天病了。否则，我就参加运动会了。He telephoned to inform me of your birthday，or I would have known nothing about it(连词)他打电话通知了我你的生日，否则，我对此一点都不知道。A man who stopped drinking water would be dead in about seven days(定语从句)一个不喝水的人在七天内就会死亡。I should have given you more help，but I was too busy(连词)我本应该帮帮你，但我(那时)太忙了。5even if，even though也可用于虚拟语气，其形式与if从句在虚拟语气中的形式相同。题组训练 单项填空：If I were to do it, I _ it in a different way.A. shall do B. will doC. would do D. have doneIf you asked your father, you _ permission.A. may get B. might getC. should have got D. may be getIt is hard for me to imagine what I would be doing today if I in love at the age of seven, with the Melinda Cox Library in my hometown.A. wouldnt have fallen B. had not fallenC. should fall D. were to fall _ I you, I would go with him to the party.A. Was B. Had beenC. Will be D. Were _ the English examination I would have gone to the concert last Sunday.A. In spite of B. But forC. Because of D. As forWithout electronic computers, much of todays advanced technologyA. will not have been achievedB. have not been achievedC. would not have been achievedD. had not been achieved二、虚拟语气在名词性从句中的运用1用于宾语从句中(1)wish后面的宾语从句一般用虚拟语气，表示一种不可能实现的愿望。其谓语动词构成形式为：过去时(宾语从句动作与wish同时)过去完成时(宾语从句动作先于wish)could/would/might+动词原形，即过去将来时(宾语从句动作后于wish)如：I wish(that)I were a bird and could fly freely in the sky我希望我是只小鸟能在天空自由飞翔。I wish(that)I had met that film star yesterday我希望昨天见到那个影星了。How I wish it werent raining now我多希望现在没下雨啊。此外，用于if only + 句子=How I wish + that从句。又如： If only I were a flying bird! =How I wish I were a flying bird!我要是一只飞鸟该多好啊!If only I had seen the film!=How I wish I had seen the film!我要是看了那部电影多好啊!题组训练 单项填空：How I wish I _ to my parents advice.A. listening B. listenC. am listening D. had listenedLook at the terrible situation I am in! If only I _ your advice.A. follow B. would followC. had followed D. have followed(2)用于表示建议、愿望、命令等词后的宾语从句中，常见的动词有：demand，order，require，insist，suggest，propose，advise等。宾语从句中的虚拟语气结构为“should+动词原形”，should可以省略。如：He suggested that we(should)start off early the next day他建议我们第二天早点出发。They insisted tha