1、 1情态动词与虚拟语气用法详解一 情态动词主要特征：1 ）不能单独作谓语，只能和行为动词或系动词连用，构成谓语；2）没有人称和数的变化，时态也只限于一般现在时和一般过去3）后面接动词原形，即不带 to 的不定式；二情态动词的基本用法1.must（1） “必须，一定，得 ”，表示的是命令性的语气。Eg.You must hand in your composition today. *回答 must 引起的一般疑问句，如果是否定意思，常用 neednt。Eg.-Must I come at four oclock?？-Oh, no, you neednt come at four.。*用 mus
2、tnt 则表示“禁止 ”。Eg.Cars mustnt park in front of the entrance. （2）表示“ 偏要，硬要” 做某事。表示与说话人的意愿相反和不耐烦的语气Eg.As I was about to start to work, the telephone must ring. must 与 have to 区分：must 更强调说话者的主观意愿；have to 则强调客观上的必要性，常译为“不得不” ，而 have to 可以有多种时态变化。2.can （1）表示能力。 Eg.I can swim across the river when I was you
3、ng. （2）表示客观（理论）上的可能性，用于肯定句中。Eg.Anybody can make mistakes. （3）表示请求和允许，怀疑多用于否定与疑问结构中：Eg.-Can I go now? -Yes, you can. Can the news be true? 重点短语：1)cannot but do sth. 表示“不得不，只好”Eg.I cannot but choose to go with them. 2)cannot/ can never.enough/too 表示“再也不为过”：Eg.You cannot be too careful to cross the roa
4、d. 3)can not help but do, can not help doing 表示“不得不” “禁不住”：Eg.The girl couldnt help but live on herself. 3.may （1）表示可能，意为 “或许，也许 ”Eg.She may come to your birthday party tomorrow. （2）表示允许、许可。否定回答时，一般要用 mustnt，表示“禁止，阻止”：Eg.-May I watch TV after supper?-Yes, you may. / No, you mustnt. （3）可以用于祈使句，表示祝愿：M
5、ay we never forget each other. may/ might as well do sth. “最好，满可以，倒不如”：Eg.Its too late. You might as well not go. 4.dare 既可作情态动词，又可作实义动词。情态动词 dare 多用于否定句、疑问句以及条件句，过去式为 dared。 实义动词 dare to do2I dare say 为固定短语，表示“我认为，我相信”Eg.My sister darent go out when night falls. Eg.Do you dare to drive a car on suc
6、h a crowded road?5.need 既可作情态动词，又可作实义动词。情态动词 need 多用于否定句、疑问句以及条件句，其肯定回答用 must，否定回答用 neednt。need 作实义动词时，注意：need to do：需要做某事，主动need doing= need to be done 需要被做，被动 6.shall （1）用于第一、三人称的疑问句中表示说话人征求对方意见和向对方请示；Shall I send you the book?（2）用于第二、三人称的陈述句，表示说话人给对方的命令、警告、允诺或威胁等。You shall fail if you dont work h
7、ard. （3）should 表示“应该；假使；万一；竟然”You shouldnt drink and drive. 注意 Why/ How should 表示说话人对某事不能理解、感到意外、等意为“竟会” 。Eg.Why should you be so late today?（4） ought to 表示职责和义务，常译作“应该”否定形式：ought not to/ oughtnt to 一般疑问句形式：将 ought 置于主语前Ought I to make an apology to Joan?7.will, would（1）表示征求对方 (第二人称)意见或询问对方意愿 would
8、比 will 更客气委婉Eg.Will you have some more wine?Eg.Would you mind my smoking here?（2）will 表示习惯性动作或某种倾向 would 表示过去习惯性动作或某种倾向Eg.Fish will die out of water.Eg.When I was young, I would play badminton on Sundays.（3） will 表示意愿 决心Eg.I will never do that again.三常见的表示推测的情态动词用法比较情态动词 适用形式 适用时态 意义 语气轻重must 只用于肯定句
9、must +domust+be doing must+have done一定，肯定语气最重can/ could 常用于疑问句和否定句cannt/couldnt+docannt /couldnt+be doing cannt /couldnt +have done可能，能够语气次之may/ might 可用于肯定句、否定句和疑问句may/ might +domay/ might +be doing may/ might +have done也许，可能语气最轻33. “情态动词 +have done”的用法构成 用法 举例must + have done 表示对过去发生的事情十分肯定的推测。mus
10、t表示推测时，不能用于否定句和疑问句。The man must have stayed up. 。should/ ought to + have done 用于肯定句，表示 “本来应该 的（但实际上却没有 ） ”，含有责备的意思；用于否定句意思为“本来不该的（但实际上却已经了）”。Perhaps we should have taken the other road. It might have been quicker. You shouldnt/ ought not to have let him do that; he might have got lost. may/ might +
11、have done 用于肯定句和否定句，表示对过去发生某事的可能性推测，意思为“或许（已经）”He said that she might have missed the plane. cannt / couldnt + have done 多用于否定句和疑问句，表示对过去某事发生的 t推测，意思为“不可能（已经）了He cant / couldnt have seen her there. could+have done 用于肯定句，表示本能做某事却没做You could have helped him.neednt + have done 表示对过去已经做了某事而后悔，意思为“本来可以不必
12、的（可实际上却已经了） ”。We neednt have worried. 我们本不必担心。虚拟语气语气：是动词的一种形式，表示说话人对发生的动作或所处的状态持有的态度.英语中有三种语气：陈述语气（陈述事实） 祈使语气（祈使句中）虚拟语气：表示说话人的假设，猜测，而不是客观存在的事实。注意：虚拟语气的 be 无论主语是第几人称均为 were一 If 型虚拟（非真实条件句中的虚拟语气）If 条件句可分为两类：真实条件句,非真实条件句非真实条件句表示的是假设的或实际可能性不大的情况，故要用虚拟语气。情况 if 从句谓语 主句谓语 例句与现在事实相反 did would/could/ If I we
13、re you, I 4should/ might + dowould follow his advice. 与过去事实相反 had + done would/could/ should/might+ have doneIf we had driven in turn, you wouldnt have got so tired. 。与将来事实相反 didshould + dowere to + dowould/could/ might/ should + doIf it snowed/ were to snow/should snow tomorrow,We would take photos
14、. 三种特殊情况1）倒装的条件句：若条件句中有 were, had, should 时，可把 if 省略，而把 were, had, should 提到主语前，形成倒装的条件句。Eg.If I were you, I would take this job. Were I you, I would take this job. 注意：如果倒装的条件句的谓语动词是否定形式时，不能用动词的缩略形式。( ) Werent it for the expense, I would go abroad now. ( ) Were it not for the expense, I would go abr
15、oad now. 2）错综虚拟条件句：有时主句和从句的谓语动词指不同的时间，在这种虚拟情况下，动词形式应根据实际情况灵活使用，尤其要注意提示语、时间状语等。Eg.If you had taken my advice then, you wouldnt be in trouble now. 3）含蓄条件句： 介词或介词短语，如 without, but for, but that,otherwise等词引起的短语和句子，暗含着 if 从句的意思，用虚拟语气。Eg.But for your advice, I wouldnt have made such great progress. = If
16、it hadnt been for your advice, I wouldnt have made such great progress. You didnt come yesterday; otherwise you would have seen him. if only（要是就好了）用虚拟语气，相当于 if 的从句If only she would listen to me carefully. 二.should do 型虚拟1.主语从句：（1）It is/ was important (necessary, essential, impossible, natural, odd,
17、vital, amazing, strange, surprising 等）that.（2）It is/ was suggested (requested, required, ordered, proposed, decides 等） that. （要求、命令、建议、意图、决定、推荐）Eg.It is advised that one (should) take plenty of boiled water. （3）It is/ was a pity (a shame, an honor, a surprise, no wonder 等）that.2.宾语从句：表示要求、命令、建议、意图、决
18、定、推荐等意义的动词，如 insist, demand, 5desire, require, request, propose, suggest, command, order 等，后面的宾语从句要用虚拟语气，其谓语形式是“(should+)动词原形” 。The commander ordered that the bridge (should) be blown up. 注意：insist 作“坚持要 ”讲时，宾语从句用虚拟语气；作 “坚持认为，坚持说”时，则不用虚拟语气。Eg.The little boy insisted that he hadnt broken that glass.
19、suggest 作“ 建议”讲时，宾语从句用虚拟语气，而作“暗示”讲则不用。Eg.The smile on his face suggested that he agreed to this plan. 3.表语从句：（1）与表示 “要求、命令、建议、意图、决定、推荐”的词相对应的名词（如decision,suggestion, proposal, advice, demand, order, requirement 等）作主语时，后面的系表结构中表语从句中的谓语常用“(should+) 动词原形”结构。Eg.Our decision is that the meeting (should)
20、be put off. 4.同位语从句：表示“要求、命令、建议、意图、决定、推荐”的名词如decision, suggestion, proposal, advice, demand, order, requirement 等后的同位语从句的谓语常用“(should+)动词原形”结构。Eg.They made a suggestion that they (should) hold an English speech contest.三.特殊情况1.wish 后的宾语从句中常用虚拟语气，表示未实现的或不可能实现的时间 Wish 后从句现在 过去时 did过去 过去完成时 Had done将来
21、Would/might doEg.I wish I knew his telephone number. Eg.He wishes he hadnt said anything unpleasant. Eg.We wish you would be quiet. 注意：as if/ as though 也可引导表示事实或有很大可能性是事实的从句，用法与 wish 相同Eg.Mary speaks Chinese as if she were Chinese.3.would rather 后的宾语从句要用虚拟语气，表示现在或将来的情况用一般过去时；表示过去的情况用过去完成时。Eg.Id rath
22、er we had a rest now.6.定语从句：在 Its (high) time that. 中谓语要用虚拟语气，可用过去式，也可用“should+ 动词原形”形式。2012 高考英语单选题分类汇编 情态动词与虚拟语气【12 全国卷 II】Im going to Europe on vacation together with John if I _ find the money.A. can B. might C. would D. need【12 重庆】-_you interrupt now? Cant you see Im on the phone?-Sorry Sir, bu
23、t its urgent.6A. Can B. Should C. Must D. Would【12 全国】I _use a clock to wake me up because at six oclock each morning the train comes by my house.A. couldnt B. mustntC. shouldnt D. neednt【12 北京】We _ the difficulty together, but why didnt you tell me?A. should face B. might face C. could have faced D
24、. must have faced【12 福建】We lost our way in that small village, otherwise we _ more places of interest yesterday.A. visited B. had visited C. would visit D. would have visited【12 陕西】If my car _ more reliable, I would have driven to Lhasa instead of flying last summer.A. was B. had been C. should be D
25、. would be 【12 陕西】23. I _ thank you too much for all your help to my son while we were away from home.A. wont B. cant C. can D. will【12 山东】If we _ adequate preparations, the conference wouldnt have been so successful.A. havent made B. wouldnt make C. didnt make D. hadnt made【12 湖南】Sorry，I am too bus
26、y now. If I _ time, I would certainly go for an outing with you.A. have had B. had had C. have D. had 【12 天津】Its quite warm here; we _ turn the heating on yet.A. couldnt B. mustnt C. neednt D. wouldnt 【12 天津】 We would have called a taxi yesterday if Harold _ us a ride home.A. didnt offer B. wouldnt
27、offer C. hasnt offered D. hadnt offered 【12 江西】We _ have bought so much food now that Suzie wont be with us for dinner.A. may not B. neednt C. cant D. mustnt 【12 辽宁】One of our rules is that every student _ wear school uniform while at school.7A. might B. could C. shall D. will【12 辽宁】Jack is a great
28、talker. Its high time that he _ something instead of just talking.A. will do B. has done C. do D. did 【12 四川】I got close enough to hear them speaking Chinese, and I said “Ni Hao ” just as I _ do in China.A. must B. might C. can D. should 【12 浙江】Had they known what was coming next, they _ second thou
29、ghts.A. may have B. could have C. must have had D. might have had【12 江苏】Days later, my brother called to say he was all right, but _ say where he was.A. mustnt B. shouldnt C. wouldnt D. mightnt【12 江苏】-Happy birthday!- Thank you! Its the best present I _ for.A. should have wished B. must have wished.
30、C. may have wished D. could have wished2011 年高考题1. I dont really like James. Why did you invite him? （北京 24 ）Dont worry. He come. He said he wasnt certain what his plans were.A. must not B. need not C. would not D. might not2. -Shall I inform him of the change of the schedule right now? (福建 25)- I a
31、m afraid you _, in case he comes late for the meeting.A. will B. must C. may D. can3. -No one _ be compared with Yao Ming in playing basketball.-Oh, you are really his big fan. (湖南 28)A. can B. need C. must D. might4. If you _ go, at least wait until the storm is over. (辽宁 21)A. can B. may C. must D
32、. will5. If you smoke, please go outside. (全国卷 8)A. can B. should C. must D. may6.- Will you read me a story ,Mummy? ( 陕西 24) - OK. You _ have one if you go to bed as soon as possible. A. might B. must C. could D. shall7. - Hows your new babysitter? (浙江 11)- We _ ask for a better one. All our kids l
33、ove her so much. A. should B. might C. mustnt D. couldnt88. - Why didnt you come to Simons party last night? (重庆 25)-I want to, but my mom simply _not let me out so late at night.A. could B. might C. would D. should 9. The police still have I found the lost child, but theyre doing all they . (四川 20)
34、A. can B. may C. must D. should 10. They have arrived at lunchtime but their flight was delayed. (32)A. will B. can C. must D. should11. -Where are the children? The dinners going to be completely ruined.-I wish they always late. （北京 28）A. werent B. hadnt been C. wouldnt be D. wouldnt have been12. M
35、aybe if I science, and not literature then, I would be able to give you more help. (北京 30) A. studied B. would study C. had studied D. was studying 13. - Pity you missed the lecture on nuclear pollution.- I it, but I was busy preparing for a job interview. (福建 34)A. attended B. had attended C. would attend D. would have attended14 I _ through that bitter period without your generous help. ( 陕西 22) A. couldnt have gone B. didnt go C. wouldnt go D. hadnt gone15 I _ sooner but I didnt know that they were waiting for me. (天津 15)A. had come B. was coming C. would come D. would have come
