情态动词教案.doc

情 态 动 词 1. 动词主要分为四类：实义动词，系动词，助动词，情态动词：（1）实义动词：有实在意思，如run, ump, say, sleep, think, accept.（2）系动词：包括be动词和感官动词，如am, is, was, look, sound, taste, smell, seem.（3）助动词：无实在意思，作为组成句子结构一部分，如do，will，have（用在完成时）（4）情态动词：表感情，只有一半意思，后面要跟实义动词才有一个完整的意思，没有人称的变化，而且情态动词后的实义动词要用原形（除ought外）。（5）dare和need均可做实义动词和情态动词。若dare和need作情态动词用时，一般用于否定形式，且比作实义动词用时更具感情色彩，没有了实义动词客观的意味。（助动词与情态动词）动词表示动作形态，但英语里有些动词并不表示动作形态，而是协助主动词表示时态（tenses）或语态（voices）。这些动词如“ do, is, have”等，叫助动词（auxiliary verbs）。另外有些动词如“can, will, may, must”等，则可协助动词表示语气或情态，叫情态动词（modal verbs）。助动词和情态动词都是特殊动词，非常有用。没有了它们，疑问句不能成立，否定句也难形成。没有了“have, has, had”完成时态（perfect tenses）无法存在；没有了“be, is, are, am, been, was, were, being”，何来被动语态（the passive voice）？请看下列例子，就知道梗概了： -What do you do every day?-I teach every day. -Can they speak English?-Yes, they can. -Will he do it?-No, he wont. -John lived here before.-John did not live here before. -Betty has completed her work on time.-She is really good. -After I had eaten my breakfast, I went to office.-How about Nancy? Did she do the same? -Jason is writing a new book.A new book is being written by Sam, too. -The cat caught a rat.-A rat was caught by a cat.此外，助动词和情态动词还有下列用途：构成疑问句附加语，如： Mr Chen has not become a businessman, has he? Jasons lectures are clear and easy-to-understand, arent they?构成简短答语，如： -Who can answer this question?-Sam can. -Will you help us with the gardening? -Yes, I will. /No, I wont. -I have seen that film before. -So have I. -William isnt a hypocrite.-Neither is his wife.构成省略句，如： I cant understand him. Can you ? The boss doesnt often come to the factory and when he does, it is generally on Sunday.除了“do, be, have”之外，作为第三人称现在时态（third person present tense）时，助动词和情态动词语尾不起变化，也就是不必有“-s”这形式。例如：I can write English. He can write English, too.Tom will know soon, but he will never know.All of you may go. Jack may also go if he wants to.（注意“be”代表其他几个助动词：is, am, are, was, were, being, seen）总而言之，助动词和情态动词，随处可见，出现率高，不难使用，也不会有什么错误。2. can / could：（1）表示脑力或体力上的能力。Nobody can stop the development of science .谁也无法阻止科学的发展。She can sing that song in English.她能用英文唱那歌。He can submerge to a depth of about twenty meters .他能潜入约二十米深的水中。He could hardly support his family before he found the new job .他在找到那份新工作前几乎无法养家。I could not understand the lecture on the computer given by Mr. Smith .我听不懂史密斯先生作的那个关于计算机的讲座。（2）表示主观上的允许，许可。意为“可以”；could表示更加委婉的请求或许可。Can I ask you some questions about it ? 我可以问你有关这件事的几个问题吗？You can not leave here till I come back .直到我回来你才能离开。Such kind of thing cant happen any more later . 这类事以后不准再发生了。Can you tell me how to get to the airport ? 你能告诉我怎么去机场吗？Could you tell me how to get to the airport ? 您能告诉我怎么去机场吗？Could I be forgiven my negligence ? 请原谅我的疏忽，行吗？（3）表示客观上的可能性。You can borrow this useful book from the library .你可以从图书馆借到这种有用的书。A more suitable person than him for the job can not be found . 不可能找到比他更适合这份工作的人了。Now people can skate on the lake .现在人们可以在湖上滑冰了。When the storm stopped , the plane could take off .当风暴停下来时，飞机可以起飞了不得。（4）表示猜测、怀疑或惊诧（用于否定句、疑问句或感叹句中）。How can / could you be here ? 你怎么会在这儿？She couldnt / cant be so stupid to do that .她不可能蠢得去做那种事吧。He couldnt / cant be over seventy .他不可能有七十多岁了。Where could / can the boy be now ? 那孩子现在能在哪儿呢？（5）情态动词后面接进行式和完成式（一般用于疑问句和否定句）。“进行式”表示动作正在发生或进行；“完成式”则表示动作是发生在过去或是表示按理是发生了但事实上却没有发生。can后面接进行式 表示可能正在发生的动作；can后面接完成式 表示可能已经做了某事。could后面接完成式 表示本可能发生或本可以做的事而没有发生或没有做；它的否定形式则表示本不可能发生或本不可以做的事而已经发生或已经做了。What can she be doing at this moment ? 这个时候她会在做什么呢？You cant be telling us the truth.你不可能在对我将真话。Can he be still thinking of it I told him ? 他会不会还在考虑我告诉他的那件事呢？He cant have left home because the television is on .因为电视还开着所以他不会离开家了。Where can they have gone ? 他们会去了哪儿呢？You cant have finished the novel so soon .你不可能这么快就看完了那本小说。The output could have been increased by 15% .产量本可以提高百分之十五的。How could he have forgotten him birthday ? 他怎么会忘了自己的生日呢？Judging from her appearance and manner, she couldnt have been over fifty years old .从她的仪表和举止来看，她不可能已有五十多岁了。（6）could还常用于表示较客气委婉的看法、提问及用于虚拟语气的结构中。这时候，could就不可以看作是can的过去式了。而是could自己独特的用法。Could you speak a little slowly ? 您能稍微说慢一点儿吗？Im afraid that we couldnt give you any definite answer at this moment .恐怕我们这时候还无法给予您任何确切的答复。I could come earlier if asked .如果要让我早一点来，我可以来早一点。We would appreciate it if you could offer us any help . 如果您能为我们提供帮助的话，我们将不甚感激。You could have done better if you had worked harder at it . 如果你再加把劲，本来可以干得更好一些的。3. may / might：（1）表示允许，许可。A：may / might可以表示允许别人做某事；B：可以表示征求对方的许可（这时may和might无时态之分， might比may更没有把握）；C：表示“法律、条文”等的许可；D：机关、学校等的文书、公告里的“不得、禁止”在正式场合下不用cannot，而用may not或musnt。May I come in ? 我可以进来吗？回答：Yes , please .请进。Sure . / Certainly . .请进。Please dont . .请不要进来。No , you mustnt .不行。（如果用may，以免显得太严厉、或不太客气）Id like to have a smoke here if I may .如果可以的话我想在这儿抽一支烟。The librarian told her that she might return the book to the library in three days .图书馆理员告诉她说，她可以在三天后还那本书。At the press conference , a news reporter asked the chairman if she might trouble him with a question about Taiwan issue. 在记者招待会上，一位新闻记者问大会主席她是否能提一个有关台湾问题方面的问题。（2）表示可能性。表示对现在、过去或将来的推测。Might表示的可能性比may稍微小一些。I may be busy from tomorrow on . 从明天起我可能会忙起来。You may catch sight of the sunrise from here when you get up before 5 in the morning .你在早晨五点钟以前起来，或许能从这儿看到日出。I wondered if they might agree with the idea .我想知道他们是否会同意这种想法。She thought it might be wise to try her luck here .她认为在这儿碰碰运气也不错。（3）表示祝愿 May that day come soon .但愿这天早日到来。May you succeed in winning the first prize in the game .祝愿你比赛夺冠成功。May you continue in your efforts and achieve greater successes .祝愿你继续努力并取得更大的成功。（4）might也常用于表示目的等状语从句中，或用于虚拟语气的结构中 I could not convince him , try as I might .我无论用什么样的办法也不能说服他。They left off earlier on that day so that they might catch the first train . 那天，他们为了赶上头班车动身早一些。He died so that the others might live .为了其他的人能活下去，他自己牺牲了。If you had made better use of your time , you might have learned more .假若你将自己的时间利用得更好一些，你本可以学到更多东西的。One error in calculation might ruin the whole project .计算中出一点错就可能毁掉整个工程。（5）may / might后面接进行式表示可能正在发生的动作（might比may更加不确定）；may后面接完成式 表示可能已经发生的动作；might后面接完成式，表示本可能发生或本可以做的事而没有发生或没有做。Your mother may be waiting for you to return home .你妈妈可能正等着你回家吧。 She may be leaving for New York tomorrow or some day . 她或许明天或者什么时候会动身去纽约。They may be returning back before Christmas .他可能圣诞节前回来。They might be planning to make a loan for their new project .他们也许在为他们的新项目策划贷款的事。She might still be crying for being wronged .她或许因为受了冤枉还在啼哭。You might be telling me a lie .你也许在对我撒谎。 He may have had some training in Chinese Gongfu .他可能学过一些中国武术。You may have narrowly missed her on your way to here.你可能在来这儿的路上刚好与她错过了。They may have seen that movie.他们或许看过那部电影。They might have finished their work by now .他们现在或许已经完成任务。She might have done better than that .你本可以做得比这更好一些的。You might have learned morefrom him . 你本可以向他学到更多一些东西的。4. will / would：（1）表示意志、愿望或决心。Would用于过去的情况。Go where you will .去你想去的地方吧。 I will pay you at the rate you ask .我会按你要的利率付给你钱的。 He wouldnt let the doctor take his blood pressure .他不愿意让大夫给他量血压。 They had to obey whether they would or not .他们不得不遵从他们的意愿。We will never talk about that subject again .我们决不会再谈论这个话题了。 I will make this computer work even if I have to stay up all night .我即使整晚不睡也一定要让这台计算机工作起来。（2）表示习惯、倾向或特性，（可译成“总是会、老是，等” ）。Will用于现在；would用于过去，带有主观性。Sometimes the cat will lie there all afternoon .有时侯，那只猫总是整个下午都躺在那儿。 Oil and water will not mix .油和水决不能调和。He would sit there for hours , doing nothing at all . 他总是在那儿一坐就是几个小时，什么都不干。（3）用于第二人称疑问句，will / would you表示请求或要求；wont you强调邀请的语气；would比will更客气、委婉。Will you tell her that Ill be back in twenty minutes ? 请告诉她我二十分钟后回来，好吗？If you want help, just let me know , will you ? 你需要帮助就告诉我，好吗？Wont you come in and have a little whisky ? 你要不要进来喝一点儿威士忌？（或：你进来喝一点儿威士忌，好吗？）Would you tell me how to get to the shopping center ? 您能告诉我怎么去购物中心吗？（4）表示猜测（可译成“一定是、想必，等” ）This will be the house youre looking for .这想必就是你要找的房子吧。He will have gone back to New Zealand .他一定是回新西兰去了。The person you mentioned would be the father , is that right ? 你说的那个人一定是爸爸了，对吗？That would be in 1999 , I think .那大概是在1999年吧。（5）would常用于虚拟条件句，表示与事实相反或不太可能实现的情况But for your help we would have been late.要不是你帮忙我们就迟到了。Well , I wouldnt worry about it . It wont do me any good .好了，我不会担心那件事的，因为它不会给我带来什么好处。（6）可用作助动词，表示将来。5. shall：（1）表示请求或征求对方的意见，用于第一人称和第三人称的疑问句中。（2）表示说话人给对方的许诺、命令、决心、警告、威胁等，用于第二人称和第三人称。 You shall hear everything directly you come .你一来就可以听到一切了。“Whatever you want you shall have , ”said the Fairy .仙女说：“你想得到什么，你就可以有什么。”I dont want to be hard on your daughter ; she shant be pressed . 我不想对你女儿太严厉，她不会太受压的。I promise that you shall see her again before long .我保证你不久就能再见到她。You shall come to my office immediately .你必须马上来我的办公室。She shall not stay in my garden .她不可以呆在我的花园里。He shall not come into my study . 不许他进我的书房。You shall do as you are told .按告诉你的那么做。That day shall come .那一天一定会到来。It has been decided that he shall be given the job .肯定给他那份工作的事已经定下来了。This law shall come into effect on January 1st 2001 .这个法律于2001年元月1日生效。（3）在条约、规定、法令等文件中表示“有义务”或“应该、必须”。只用于第三人称。Each competitor shall wear a number .每个参赛者要佩戴一个数字标。The renter shall keep the house in a neat and orderly state . 租赁者要保持房屋整洁有序。The supplier shall make shipment before October and the purchaser shall make payment within 15 days after receipt of the goods .卖方十月以前装运，买方在收到货物后十五天内付款。6. should：（1）作为shall的过去式，用于第一人称和第三人称，表示请求或征求对方的意见，多用于间接引语中以征求对方的意见。（2）表示出于职责、义务该做某事You shouldnt come to such a decision hastily .你不应该匆匆忙忙地作出这么一个决定。You should write to your parents at least once a month .你应该至少每月给你父母亲写一封信。We should read English aloud every morning .我们应该每天早晨朗读英文。They should do it for their own good . 为了他们自己利益他们应该做这件事。（3）表示说话人特殊的情感，如惊奇、愤怒、失望等。I think it is dreadful that anyone should be so miserable.我认为，竟然每个人都如此伤心就太糟糕了。Why should I pay him for nothing ? 我干吗要无为地付给他钱？It seems so unfair that this should happen to me .这件事竟然发生在我身上似乎太不公平了。Its strange that it should be so cold today . 奇怪，今天怎么会这么冷。（4）表示对某种情况的估计She shouldnt be out in such an early morning .她不会这么一大早就出去了吧。The effect of the tax should be felt in higher prices .人们可能会从各种上涨的物价中感觉到这种税的影响的。The event should lead them to a even worse economic crisis.这次事件可能会将他们引向更严重的经济危机。This book should be published in two months at most .这本书最多两个月后就会出版的。（5）用于某些从句中表示虚拟语气The doctor insisted that the girl should be hospitalized .大夫坚持认为那个女孩要住院治疗。If it had not been for the doctors care the girl should not be speaking to you now .要不是由于大夫的精心照料，这个女孩现在就不能与你说话了。She stood away so that he should enter the room first . 她让到一边，好让他第一个进入房间。Ill write it down lest I should forget it .我将它记下以免遗忘。Take an umbrella with you in case it should rain .带上雨伞，以防万一下雨。（6）should后接完成时（should have done sth 本该做某事而未做 ； shouldnt have done sth 本不该做某事而做了）should后面接进行式表示应该正在做某事。You should be doing your exercises instead of watching TV. 现在你该在做作业而不是看电视。You shouldnt be thinking about the solution only in one way .你不应该只用一种方法考虑解决问题的办法。Why should I be waiting here without doing anything ?我凭什么在这儿白等。7. must：（1）表示“必须、应该、一定”，指出于主观意识上认为应该做某事。We must speed up the pace of our economic reform .我们必须加速经济改革的步伐。We must keep steps to the scientific development .我们一定要与科学的发展保持一致步调。You must hurry up or youll be late .你必须得快点儿，不然会迟到的。（2） 表示出于职责、义务该做某事 We must protect peoples rights .我们应该保护人民的利益。Everyone must be loyal to his motherland .每个人都应该忠于自己的祖国。You must serve the people when you grow up .你们长大成人时应该服务于人民。Students must work hard at their study .学生应该努力学习。（3）表示命令，指说话者主观的命令或强烈的劝告。（4）musnt表示禁止、不许、不应该。表示没有义务时用dont need to / dont have to / neednt。You must not speak ill of others .你一定不要说别人的坏话。Cars must not parked here . 这里禁止停车。Smoking must not allowed in the office .严禁在办公室吸烟。You mustnt talk to girls like that .你绝不能那样对女孩子说话。（5）表示猜测、推测must常用于肯定句中表示猜测。对现在或未来的事进行猜测时，后接动词原形，否定形式用cant / couldnt。must后面接进行式 表示想必正在做某事，用于对正在进行的动作的推测和对过去情况的肯定推测（表示显然或必然的结论或有把握的推测），意为“想必正在做”。must后面接完成式，对已经发生的事进行猜测时，表示想必已经发生的事。You must be tired after working so long .你工作这么久以后，肯定累了吧。It must be that naughty boy crying outside .肯定是那个调皮的孩子在外面大叫。The idea must be accepted by the society sooner or later.这种想法肯定或迟或早会被社会所接受的。It must have rained last night for it is so wet outside .外面这么湿，昨晚肯定下雨了。I didnt see you in class yesterday. You must have been absent .我昨天上课没见着你，你肯定没有来。You must be thinking where I learned it .你一定在想我是从哪儿知道这件事的。They must be following us just a little behind us .他们肯定在离我们不远的地方尾随着我们。My brother must be sleeping in bed for its so quiet in the house .家里这么安静，我弟弟一定在床上睡觉。You must have talked about it with her before hand .你一定事先与她谈过这件事。It must have snowed last night for its so cold this morning . 今天早晨这么冷，昨晚一定下雪了。（6）表示“偏偏、偏要、硬要”，指做令人不愉快的事情。8. ought to do ：（1）表示出于职责和义务做某事。指说话者认为“应该做某事”。You ought not to be so careless in your work .你不应该在工作上如此粗心大意。We ought to study hard for the sake of our motherland.我们应该为了我们的祖国而努力学习。His doctor said to him that he oughtnt to smoke so much .他的大夫说他不应该抽这么多烟。Oughtnt you to give us a chance to try ?你难道不应该给我们一个尝试的机会吗？（2）表示极有可能发生某事As an auto repairman , Dick ought to know what is wrong with the car .狄克作为一个汽车修理工总该知道这部车的毛病所在吧。If we set off right now , we ought to be able to get there in time .如果我们马上出发，我们应当能够按时到达那里。Tomorrow ought to be a nice day for we have such a fine sunset today .今天有这么好的晚霞，明天准是个晴天。（3）表示说话者按照一定的依据进行推测，意为“按道理说应该”。（4）其否定形式为ought not to；疑问形式是将ought提到主语的前面。（5）ought to后面接完成式表示本应该发生或本应该做的事而没有发生或没有做；它的否定形式则表示本不应该发生或本不应该做的事而已经发生或已经做了。例如：They ought to have completed their work much earlier .他们本应该在更早一些的时候完成他们的工作的。You oughtnt to have left your keys in the office when you went out .你不该出去的时候将钥匙留在办公室里。I ought to have said it to her in a calmer mood .9. have to：意思接近于must，但have to更强调客观上的必要性，表示习惯性动作或者一次性具体的某个动作。常译为“不得不”。而且还可以有更多的时态形式，也可以与情态动词连用。否定是为dont have to，疑问式借助于助动词do。Have to可以代替have got to。have got to 指标是一次性的、具体的某个动作，不能与always，usually等词连用，其否定形式为havent got to，疑问形式是将have提到主语之前。I have to go now for Ive got a meeting 15 minutes later.我现在必须要走了，因为我15分钟后有个会要开。He has to be back home by five to fetch his son from kindergarten . 他必须在五点前回家去幼儿园接他儿子。Jenny had to tidy up the room before her mother came back . 珍尼不得不在她妈妈回家以前将房间整理好。Well have to reconsider the whole thing .我们将不得不重新考虑整个事情。10. need：（1）在否定句中表示“不必”。（2）在疑问句中表示“需要”，这时的肯定回答用must，否定回答用neednt。（3）neednt have done表示“本没有必要做某事而做了”。There are still one and a half hours to go , we neednt be in such a hurry .还有一个半小时，我们无需如此慌慌张张。I hardly need say how much we missed you .不用说我们是多么想念你啊。Need you go so soon ?你需要这么早就去吗？You need have no anxiety on my account .你不必为我而着急。11.dare , dared（用于否定句、疑问句和疑问句）敢Dare you stay here alone in the night ? 你敢在夜里呆在这儿吗？Nobody dared mention that matter. 没有人敢提那件事。How dared you say that to her ? 你怎么敢对她说那件事？Even if you dare do it , I wont allow you to because its too dangerous .即使你敢做，我也会让你做那件事，因为太危险了。dare的用法详细解析:一、基本用法特点dare可用实意动词和情态动词，用作情态动词时，意思是“敢”，其后接动词原形，通常只用于否定句或疑问句以及if或whether之后，一般不用于肯定句：Dare you tell her the truth? 你敢告诉她事实真相吗? I dont know whether he dare try. 我不知他是否敢试一试。I darent ask her for a rise. 我不敢要求她加薪。【注】I dare say 是习惯说法(用于肯定句)，并不一定要译为“我敢说”，它所表示的是一种不肯定的语气，常译为“很可能”、“大概”、“我想”等，有时用作反语：I dare say (that) you are right. 我想你是对的。Oh, you mean to win? I dare say you will. 啊，你想打赢? 我且看你赢吧。(2) dare用作实意动词时意为“敢于”，可以有各种词形变化，可用于各类句型(肯定句、否定句、疑问句及各类从句等)，其后多接带 to 的不定式，有时 to 也可省去(尤其是在否定句或疑问句)，可用于非谓语形式，完成时态等：We must dare to think, speak and act. 我们必须敢想、敢说、敢做。I wonder how he dares (to) say such things. 我纳闷他怎么竟敢说出这样的话来。Did he dare (to) tell her? 他敢告诉她吗? We dont dare (to) say anything. 我们什么也不敢说。The boy stood before the teacher, not daring to look up. 这个小男孩站在老师面前不敢抬头。Ive never dared (to) ask her. 我从来不敢问她。二、dare的过去式问题情态动词dare可以有过去式dared，但也可以直接用dare表示过去式，或后接动词完成式：That was why he dared do so. 那就是他为什么敢这样做的原因。Mother dare(d) not tell father shed given away his old jacket. 母亲不敢告诉父亲她把他的旧上衣送人了。I didnt like their new house though I darent have said so. 我不喜欢他们的新房子，虽然我没敢这样说过。I darent have done it yesterdaybut I think I dare now昨天我没敢这样做，但现在我想我敢。【注】dare后通常不接动词的进行式。need的用法详解:一、基本用法特点need可用实意动词和情态动词，用作情态动词时，意思是“有必要”或“需要”，其后接动词原形，通常只用于否定句或疑问句以及if或whether之后，一般不用于肯定句：You neednt do all these exercises. 你不需要做所有这些练习。Need he do it all at once? 他需要立即做这一切吗?Need they have done it yesterday? 这事他们需要昨天做吗?Do you think you need tell her about it? 你认为有必要告诉她这件事吗?I wonder if I need bring my mosquito-net. 不知我需不需要带蚊帐。【注】(1) 由于用作情态动词的need通常不用于肯定句，所以对于以need开头的疑问句的否定回答可用neednt，但是肯定回答却不能用Yes, you need之类的，应根据具体情况改用其他表达：Need he stay here? Yes, he must. “他有必要留在这儿吗?”“是的，必须留在这儿。”(2) need有时用于含有only, all 等表限制意义的肯定句中：This is the only form you need fill in. 你要填的只有这一张表。All you need do is to take a taxi from the airport. 你只需从机场打个的即可。二、后接动词完成式的用法若要谈论过去情况，应在其后接动词完成式：You neednt have mentioned it. 你没有必要提及此事的。You neednt have come in person. 你当时不必亲自来的。Need you have paid so much? 你当时真需付那么多钱吗? 【注】(1) 在宾语从句中可直接用need表示过去(也可用didnt have to)：He said he need not didnt have to hurry. 他说他不必匆忙。(2) 注意对“need+have+过去分词”结构疑问式的回答：Need he have come so early? Yes, he had to. / No, he neednt have.“他来那么早有必要吗?”“有必要，他必须来那么早。”/“不，他本来没有必要来那么早的。”三、后接动词进行式的用法有时后接进行式表示动作正在进行：We neednt be waiting here. 我们不必在这里等。We neednt be standing here in the rain. 我们没有必要站在这里被雨淋。四、neednt have done与didnt need to do前者主要表示某事已经做了，但后来觉得没必要去做，因此常含有责备或遗憾之意；后者则不具体表明某事是否做了(即可能做了也可能没有做，此用法