情态动词的定义.doc

情态动词的定义情态动词的定义:情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语,只能和其他动词原形构成谓语。We can be there on time tomorrow.我们明天能按时去那儿。May I have your name?我能知道你的名字吗？Shall we begin now?我们现在就开始吗？You must obey the school rules.你必须遵守校规。情态动词数量不多,但用途广泛,主要有下列:can (could), may (might), must, need, ought to, dare (dared), shall (should), will (would) .情态动词的位置:情态动词在句中放在谓语动词之前,谓语动词前若有助动词,则在助动词之前,疑问句中,情态动词则在主语之前。I can see you. Come here.我能看见你，过来吧。He must have been away.他一定走了。What can I do for you?你要什么？How dare you treat us like that！你怎能那样对待我们！情态动词的特点:情态动词无人称和数的变化,情态动词后面跟的动词需用原形,否定式构成是在情态动词后面加not。 个别情态动词有现在式和过去式两种形式,过去式用来表达更加客气,委婉的语气,时态性不强,可用于过去，现在或将来。He could be here soon.他很快就来。We cant carry the heavy box.我们搬不动那箱子。Im sorry I cant help you.对不起，我帮不上你。情态动词的用法:1 can (could) 表示说话人能,可以,同意,准许,以及客观条件许可,could为can的过去式。Can you pass me the books?你能给我递一下书吗?Could you help me, please?请问,你能帮助我吗?What can you do?你能干点什么呢?Can you be sure?你有把握吗?can 和could只能用于现在式和过去式两种时态,将来时态用be able to来表示。He could help us at all.他完全可以帮助我们。With the teachers help,I shall be able to speak English correctly.由于老师的帮助,我将能准确地讲英语。2may (might) 可以,表示说话人同意,许可或请求对方许可。You may take the book home.你可以把书带回家去.May I come in?我可以进来吗?May I use your dictionary?我可以用你的词典吗?You may put on more clothes.你可以多穿点衣服.He said he might lend us some money.他说他可以借给我们一些钱。may 否定式为may not,缩写形式是maynt.might 是may的过去式,有两种用法,一种表示过去式，一种表示虚拟语气,使语气更加委婉,客气或对可能性的怀疑。He told me he might be here on time.他说他能按时间来。Might I borrow some money now.我可以借点钱吗?He might be alive.他可能还活着。must 用来指一般现在时和一般将来时,过去式可用have to的过去式代替。I must finish my work today.我今天必须完成我的工作。You mustnt work all the time.你不能老是工作。Must I return the book tomorrow?我必须明天还书吗?After such a long walk, you must be tired.走了这么长的路,你一定困了。He must be the man I am looking for.他一定是我要找的人。He had to go because of somebodys callinghim that day.那天他要走是因为有人叫他。must + have + 过去分词,表示现在对过去事物的推测。He must have told my parents about it.他一定把这件事情告诉我父母亲了。He must have received my letter now.他现在一定收到我的信了。Its six oclock already, we must have been late again.已经六点钟了，我们一定又迟到了。must 和have to的区别: must表示说话人的主观思想, have to表示客观需要。You must do it now.你必需现在就干。(说话人认为必须现在干)I have to go now.我得走了。(客观条件必须现在走)4 need需要 多用在否定式或疑问句中.Need I attend the meeting tomorrow?我需要明天参加会议吗?You need not hand in the paper this week.这一周你不必交论文。need 是一个情态动词,他的用法完全和其他情态动词一样,但need还可当作实义动词使用,这时need就象其他动词一样,有第三人称,单复数,后面加带to的动词等特性。I need a bike to go to school.我上学需要一辆自行车。Do you need a dictionary?你需要词典吗?She needs a necklace.她需要一条项链。neednt + have + 过去分词 表示过去做了没必要做的事情。You neednt have taken it seriously.这件事情你不必太认真。5 dare 敢 多用在否定或疑问句中。The little girl dare not speak in public.小女孩不敢在公众面前说话。Dare you catch the little cat?你敢抓小猫吗?dare 除用作情态动词外,更多的是当实义动词使用,用法同实义动词一样,要考虑人称,单复数,时态等。Do you dare to walk in the dark?你敢黑夜走路吗？He doesnt dare to tell the teacher what happened that day.他不敢告诉老师那天发生的事。6 ought应当,应该 后面跟带有to的动词不定式。You ought to read these books if you want to know how to repair the motorcar.如果你想知道如何修理汽车,你应该读这些书。You ought to bring the child here.你应该把孩子带来。ought + to have done句型。指过去动作,表示一件事情该做而未做。You ought to have been here yesterday.你昨天就应该来。ought not to have done句型。表示一件不该做的事情却做了。You ought not to have taken the book out of the reading-room.你不应该把书带出阅览室。7will (would)决心,愿望。would为will的过去式,可用于各人称。Ill do my best to catch up with them.我要尽全力赶上他们。Ill never do it again, thats the last time.我再不会做那件事情了,这是最后一次。He said he would help me.他说他会帮助我。will, would用于疑问句表示说话人向对方提出请求或询问,用would比will更婉转,客气。Its hot. Will you open the windows?天气太热了,你能打开窗户吗?Will you help me to work it out?你能帮我解这道题吗?Would you like some coffee？给你来点咖啡怎样？8 Shall, should表示命令,警告,允诺,征求,劝告,建议惊奇。You should hand in the exercise book.你应该交作业本儿了。This should be no problem.这应该没问题。Shall we go now.我们现在可以走了吗?Why should I meet him？为什么我要见他?9 have to,不得不,必须,表示客观条件只能如此,而must则表示主观思想必须。I have to go now.我现在得走了。I have to cook for my child.我得给孩子做饭。You must be here on time next time.你下次一定要按时来。We must go to get the timetable ourselves.高考常见语法虚拟语气一语气的定义和种类。1语气(mood)语气是动词的一种形式，表示说话人对某一行为或事情的看法和态度。2语气的种类a.陈述语气：表示动作或状态是现实的、确定的或符合事实的，用于陈述句、疑问句和某些感叹句。如：There are two sides to every question.每个问题都有两个方面。Were you busy all day yesterday?昨天一整天你都很忙吗？How good a teacher she is!她是多好的一位老师啊！b.祈使语气：表示说话人对对方的请求或命令。如：Never be late again!再也不要迟到了。Dont forget to turn off the light.别忘了关灯。c.虚拟语气：表示动作或状态不是客观存在的事实，而是说话人的主观愿望、假设或推测等。如：If I were a bird, I could fly in the air.如果我是一只小鸟，我就能在空中飞行。I wish I could pass the examination.我希望我能通过考试。May you succeed!祝您成功！二虚拟语气在条件从句中的用法。条件从句有两类，一是真实条件句，另一是虚拟条件句。如果假设的情况可能发生，是真实条件句，这种情况下谓语用陈述语气。如：If time permits, well go fishing together.如果时间允许，我们就一起去钓鱼。如果假设的情况是不存在的或不大可能发生的，则是虚拟条件句。如：If you had come yesterday, you would have met that famous professor.如果你昨天来，你就会见到那位著名的教授了。（隐含的事实是：你昨天没来，也没见到那位著名教授）。在含有虚拟条件句的复合句中，主从句的谓语都要用虚拟语气，现将其形式列表如下：动词形式 时间从句主句与现在事实相反动词过去式(be的过去式用were)would(could/should/might)+动词原形与过去事实相反had+动词过去分词would(could/should/might)+have过去分词与将来事实可能相反动词过去式should+动词原形were to+动词原形would(could/should/might)+动词原形注：主句中的should只用于第一人称，但在美国英语中，should常被would代替；从句中的should可用于各种人称。1表示与现在事实相反的假设和结果。如：If I were you, I should(would ,could, might)tell him thetruth.要是我是你，我就会告诉他真相了。（事实上我不是你）If she had time, she would(could, might)help me.如果她有时间，她就会帮我了。（事实上她没有时间）2表示与过去事实相反的假设和结果。如：If I had known your telephone number yesterday, Ishould(would, could, might)have telephoned you.如果昨天我知道了你的电话号码，我就会给你打电话了。（事实上我昨天不知道你的电话号码。）If you had taken my advice, you wouldnt(couldnt) have failed in the exam.如果你听了我的建议，你就不会考试不及格。（事实上你根本没听我的。3表示与将来事实可能相反的假设和结果。如：If it should rain, the crops would(could, might)be saved.假如天下雨，庄稼可能就收获了。-What would happen if I put the paper on the fire?-It would burn.-我若把只放在火上会怎么样？-纸会烧着。注：在表示与将来事实可能相反的条件从句中，were to +动词原形比较正式，常用于书面语中。如：If you were to go toBeijing, you would (could, might) have a chance to visit Tian An Men Square.三虚拟语气的其它用法。1虚拟语气在主语从句中的用法。在“It is important (strange, natural, necessary)that”这类句型中，that所引导的主语从句中的谓语动词常用 “(should)+动词原形”结构，表示某事是“重要”，“奇怪”，“自然”，“必要”等意义。如：It is important that every Beijinger (should) be able tospeak English.重要的是每个北京人能说英语。It is necessary that he (should) be sent to hospital atonce.有必要马上把他送医院。2虚拟语气在宾语从句中的用法。（1）在动词wish后的宾语从句中，表示与现在或过去的事实相反，或对将来的主观愿望，从句通常省略连词that。a.表示对现在情况的虚拟：从句动词用过去式或过去进行式(be的过去式用were )表示。如：I wish I knew the answer to the question.我希望知道这个问题的答案。（可惜不知道。）I wish it were spring in my hometown all the yeararound.但愿我的家乡四季如春。（只是愿望，实际根本不可能实现。）b.表示对过去情况的虚拟：从句动词用had+过去分词。如：I wish (that) I hadnt wasted so much time.我后悔不该浪费这么多时间。（实际上已经浪费掉了。）He wishes (wished) he hadnt lost the chance.他真希望没有失去机会。（事实上机会已经失去了，他感到惋惜。）c.表示对将来的主观愿望：谓语动词形式为 “would/should/could/might+动词原形”，此时要注意，主句的主语与从句的主语不能相同，因为主句的主语所期望的从句动作能否实现，取决于从句主语的态度或意愿（非动作名词除外）。如：I wish it would stop raining.但愿雨能停止。I wish you would be quiet.我希望你安静一些。（2）在suggest（建议）, demand(要求), order(命令), propose(建议), insist（坚持要做）, command(命令), request(要求), desire(希望)等动词后的宾语从句中，谓语动词用 “(should)+动词原形”，表示建议，要求，命令等。如：I suggest that we (should) start the meeting at once.我建议马上开会。The undergraduate insisted that he (should) go to work inthe south.这位即将毕业的学生坚持要到南方去工作。注：当suggest表示暗示，主语为something；insist表示坚持观点时，后接的宾语从句当用真实语气。比较：His silence suggested that he agreed with mydecision.他的沉默暗示着他赞成我的决定。He suggested that I (should) stick to mydecision.他建议我坚持自己的决定。He insists that doing morning exercises does good topeoples health.他坚持认为做早操对健康有益。He insists that he (should) do morning exercises everyday.他坚持他每天都要早操3虚拟语气在表语从句中的用法。当主语为advice, suggestion, order,proposal等词时后接表语从句，表语从句中的谓语动词常用“(should)+动词原形”结构，表示某人建议、劝告、命令等的内容。如：My advice is that you should practise speaking English asoften as possible.我的建议是你尽可能经常地练习说英语。The order from the commander was that the troops shouldset off for the front immediately.司令官的命令是部队立即开拔去前线。4特殊的虚拟语气结构。（1）虚拟语气用在状语从句中由as if或as，though引导的状语从句表示比较或方式时，从句中的谓语动词用虚拟语气。动词形式用动词的过去式(bewere)或had+过去分词。如：The teacher treats the student as if he were her ownchild.这位老师带这位学生就象她的亲生孩子一样。He speaks as if he had been to the UnitedStates.他说得好象他真的到过美国似的。（2）在It is time (that); Id rather (that)句型中从句的谓语动词常用动词的过去式表示虚拟语气，意思是“该干某事了，时间已经有些晚了”“我宁愿/希望”。如：It is time that we did something to stoppollution.该我们做些什么制止污染的时候了。It is time that Father picked up Lily from thekindergarten.该父亲去幼儿园接莉莉的时候了。Id rather you told me the truth.我真希望你告诉我真相。Id rather I didnt see you again.我宁愿不再见着你。（3）虚拟语气用在简单句中a情态动词的过去式用于现在时态时，表示说话人的谦虚、客气、有礼貌、或委婉的语气，常用于日常会话中。如：Would you be kind enough to show me the way to the postoffice?请你告诉我去邮局的路好吗？It would be better for you not to stay up toolate.你最好别熬夜到很晚。b在一些习惯表达中。如：Youd better set off now.你最好现在就出发。Id rather not tell you the secret.我情愿不告诉你这个秘密。c用 “may+动词原形”表示祝愿，但愿，此时may须置于句首（多用于正式文体中）。如：May good luck be yours!祝你好运！May you be happy!祝你快乐！May you do even better!祝你取得更大成就！用动词原形。例如：Long live the people!人民万岁！“God bless you,”said the priest.牧师说：“愿上帝保佑你！”5虚拟语气在同位语从句中的用法在名词advice, suggestion, order, proposal等后接的同位语从句中，谓语动词用虚拟语气，起形式为 “(should)+动词原形”，说明“建议”，“劝告”，“命令”等的具体内容。如：The order came that the work should be finished two daysahead of time.提前两天完成工作的命令传来了。Reluctantly she accepted their proposal that she should beoperated on.她勉强接受了他们要她去接受手术的建议。（一）主从句时间不一致情况下的虚拟语气(混合条件句)（二）有时条件从句中的动作和结果与主句中的动作，发生的时间不一致，这时动作的形式应根据它所表示的时间加以调整。如：If you had followed my advice, you would be able to finishthe work now.如果你当时听了我的话，现在就能完成这份工作了。（从句说明过去，主句说明现在。）If I were you, I would have gone to her birthdayparty.如果我是你，我就去参加她的生日晚会了。（从句说明现在，主句说明过去。）If you hadnt lent me some money, I couldnt have boughtthe new house and most likely I would be still living in thedangerous house now.假若你不借钱给我，我不可能买下这幢新房，很可能现在还住在危房里。（从句说明过去，主句说明过去和现在。）（二）含蓄条件句非真实条件句中的条件从句有时不表出来，只暗含在上下文中，这种句子叫做含蓄条件句。含蓄条件句大体有三种情况；1.条件暗含在短语中。如：(1)W hat would I have done without you?如没有你，我会怎么办呢？(条件暗含在分词短语without you中)(2) It would be easier to do it this way.这样做会比较容易。(条件暗含在不定式短语to do it this way中)(3) This same thing, happening in wartime, would lead toa disaster.同样的事，如发生在战时，就会酿成大祸。(条件暗含在分词短语happening inwartime中)(4) But for your help we couldnt have succeeded in theexperiment.如果没有你的帮助，我们的实验是不会成功。(暗含条件是but for your help)(5) He must have the strength of a hippopotamus, or henever could have vanquished that great beast.他一定是力大如河马，否则他绝不会击败那只庞大的野兽。(暗含条件是连词or)(6) Alone, he would have been terrified.如是单独一人，他是会感到害怕的。(暗含条件是alone)2.条件暗含在上下文中。如：(7) You might stay her forever.你可以永远待在这儿。(可能暗含if you wantedto)(8) We would have succeeded.我们本来是会成功的。(可能暗含if we had kepttrying)(9) Your reputation would be ruined.你的名誉会败坏的。(可能暗含if youshould accept it)(10) I would appreciate a little of your time.谢谢你给我一点时间吧。(可能暗含if you were so kind as to give me a little ofyour time)3.在不少情况下，虚拟式已变成习惯说法，很难找出其暗含的条件。如：(11) You wouldnt know.你不会知道。(12) I would like to come.我愿意来。(13) I wouldnt have dreamed of it.这是我做梦也不会想到的。(14) He told the story in such minute detail that he mighthimself have been an eye-witness.他将那事讲的非常仔细，简直就象他亲眼看见一样。（三）条件从句中省去if的情况在if引导的表示虚拟的条件状语从句中，常可以省略if，将had, were或should提至句首。如：Had I seen the film, I would have discussed it with themlast night.假如我看了那部电影，昨晚我就可以和他们一起讨论了。Were I a bird, I could fly freely.假如我是一只小鸟，我就能自由翱翔。Should it rain next week the farmers would have a goodharvest.要是下周能下雨的话，农民们就能有个好收成了。1He suggested that the meetingput off.A. not beB. should notC. wouldntD. be not2What would have happened if youher child?A. hadnt helpedB. couldnt helpC. wouldnt helpD. didnt help3It is strange that heso.A. thinksB. thinkC. thoughtD. will think4If Iwith her last summer, Iwith her now.A.workedam getting on very wellB. had workedwouldget on very wellC.had workedwould have got on very wellD. had workedwill get on very well5I wish Imy uncle yesterday.A. metB. have metC. would meetD. had met6The old professor gave orders that the experimentbefore 6.A. was finishedB. will finishC. be finishedD. shall be finished7Its high time hehome.A. goesB. wentC. will goD. is going to go8you succeed andyou be healthy.A. MaymayB. Wishwi