情态动词与虚拟语气

1、归纳总结归纳总结1.1.情态动词的类型及特征情态动词的类型及特征 （1 1）只作情态动词的有：）只作情态动词的有：must,can (could),must,can (could), may (might),ought to may (might),ought to。 （2 2）可作情态动词也可作实义动词的有：）可作情态动词也可作实义动词的有： need,dare;need,dare; （3 3）可作情态动词也可作助动词的有：）可作情态动词也可作助动词的有：shall shall (should),will (would) (should),will (would)。 （4 4）具有情态动词的

2、某些特征的有：）具有情态动词的某些特征的有：have/had have/had to to，used toused to。 （5 5）情态动词有一定的词义，但不能单独作谓）情态动词有一定的词义，但不能单独作谓 语，适用于主语的各种人称和数（语，适用于主语的各种人称和数（have tohave to除除 外）。外）。2.shall2.shall的用法的用法 shallshall用于二、三人称的陈述句，表示命令、允用于二、三人称的陈述句，表示命令、允 许、警告、威胁、决心等；用于一、三人称的许、警告、威胁、决心等；用于一、三人称的 疑问句，表示征求对方的意见和指示。疑问句，表示征求对方的意见和指示

3、。3.3.表能力表能力 cancan用来表示现在的或一般的能力（也可用用来表示现在的或一般的能力（也可用be be able to able to，但不如，但不如cancan普遍）；表示将来的能力普遍）；表示将来的能力 用用will be able towill be able to；表示过去一般的能力（不；表示过去一般的能力（不 表示做与未做）用表示做与未做）用couldcould或或were/was able towere/was able to； 表示过去有能力并成功地做成了某事用表示过去有能力并成功地做成了某事用was/was/ were able to were able to；表示

4、过去有能力做但未做用；表示过去有能力做但未做用 could have donecould have done。4.4.表推测（可能性）表推测（可能性） cancan用于肯定句中表客观的可能性；用于肯定句中表客观的可能性；may/mustmay/must用用 于肯定句表实际的可能性；表示否定的推测要于肯定句表实际的可能性；表示否定的推测要 用用cant/couldntcant/couldnt；表示确定（或可能有的；表示确定（或可能有的 未来或期望）用未来或期望）用shouldshould。5.5.委婉语气委婉语气 问句中问句中could,might (could,might (及及would,s

5、hould)would,should)等表示等表示 语气的委婉，但在答语中应用语气的委婉，但在答语中应用can/maycan/may。6.6.表示必要性表示必要性 表示现在或将来必须做某事用表示现在或将来必须做某事用mustmust；不必做某；不必做某 事用事用dont have to do sth.dont have to do sth.或或dont need dont need to do sth. to do sth.或或neednt do sth.neednt do sth.；当表示过去；当表示过去 没有必要做但实际上做了，用没有必要做但实际上做了，用neednt have needn

6、t have done sth. done sth.。7.“7.“情态动词情态动词+have done”+have done”用法用法 should (shouldnt) have doneshould (shouldnt) have done本来应该（不本来应该（不 该）做某事而未做（做了）该）做某事而未做（做了） could/might have donecould/might have done本来能够本来能够/ /可以做某事可以做某事 而未做而未做 neednt have doneneednt have done本来不必做某事但做了本来不必做某事但做了 must have done“m

7、ust have done“一定已经一定已经”，表示对过，表示对过 去的肯定推测去的肯定推测 cant/couldnt have done“cant/couldnt have done“不可能已不可能已 经经”，表示对过去的否定推测，表示对过去的否定推测8.8.情态动词的其他用法要点情态动词的其他用法要点 cant but+do sth.cant but+do sth.表示表示“不得不，只好不得不，只好”； may as well+may as well+动词原形，表示动词原形，表示“最好，不最好，不 妨妨”；cant (cant (或或nevernever等否定词等否定词) )与与enoug

8、h enough ( (或或too much)too much)连用，表示连用，表示“再再也不为也不为 过过”；maymay可用于祈使句，表示祝愿；可用于祈使句，表示祝愿；why (why (或或 how)+shouldhow)+should意为意为“竟会竟会”；mustmust还可表示还可表示“偏偏 要要/ /硬要硬要”做某事；做某事；mustntmustnt表示表示“禁止禁止”；对；对 以以maymay开头的问句的否定问答应用开头的问句的否定问答应用mustntmustnt；对；对 以以mustmust开头的问句的否定问答应用开头的问句的否定问答应用neednt neednt （或（或do

9、nt have todont have to）。）。1.英语动词有三种语气， 陈述语气，祈使语气和虚拟语气。2. 定义：用来表示说的话不是事实，或者是不可能发生的情况，而是一种愿望，建议，假设的语气叫虚拟语气。一、第一种类型的虚拟语气一、第一种类型的虚拟语气wish/would rather/if only/as ifwish/would rather/if only/as if 谓语动词时态原则：谓语动词时态原则：与现在与现在/ /将来相反用过去将来相反用过去与过去相反用过去的过去（过去完成时）与过去相反用过去的过去（过去完成时）I wish I were a bird. I wish I

10、hadnt make such a mistake yesterday. She loves the baby as if it were her own son.I remember the whole thing as if it had happened yesterday.If only I knew his name!If only we had followed your advice!I would rather you had changed your idea. 二、二、 表示要求，命令，建议的虚拟语气。 常见动词：一个坚持：insist两个命令命令：order, comma

11、nd 三个建议建议：advise, suggest, propose四个要求：要求：demand , require, request, desire 这些动词后面的宾语从句要使用虚拟语气用法。即从句中的动词 使用should + should + 动词原形，或者将动词原形，或者将shouldshould省略省略。注意注意: suggest: suggest表表 暗示表明暗示表明 时时 insistinsist表表坚持认为坚持认为时不用虚拟语气时不用虚拟语气1.我们建议我们建议Tom 去休息一下。去休息一下。2.他坚决要求我到场。他坚决要求我到场。3.国王命令囚犯明天要实施死刑。国王命令囚犯明

12、天要实施死刑。4.他们要求我们派他们去那儿工作。他们要求我们派他们去那儿工作。We suggested that Tom (should) have a rest.He insisted that I (should ) be present.The king ordered that the prisoners (should) be killed the next day.They requested that we (should) send them to work there.以上动词相应的名词构成的名词性从句包括主语从句，表语从句和同位语也要使用虚拟语气。从句中的动词形式一样。 o

13、rder, advice, suggestion, order, advice, suggestion, proposal, demand, request, proposal, demand, request, desiredesireIts suggested that the plan be carried out.My demand is that she should come to see me once a week.All of us are for the advice that the chemical factory should be closed down.三、三、虚

14、拟语气在条件状语从句中的用法虚拟语气在条件状语从句中的用法条件从句 If 从句的谓语形式主句的谓语形式现在过去未来过去时态过去完成时态would/could/should/might +V.(原)would/could/should/might+have+p.p.1. 过去时态与现在/将来相反用过去，与过去相反用过去的过去2. should do3. were to do1.If I had enough time , I would travel abroad.2.If I were rich, I would buy you anything you want.3. If I had ta

15、ken your advice, I wouldnt have made a mistake.4. If he had been there, it wouldnt have happened.与现在事实相反与过去事实相反5.I think we could do it, if we planed it properly and could borrow the tools.6.If it should rain tomorrow, they wouldnt go for an outing.7. If we were to have three days off , we would enj

16、oy a very happy life.与将来事实相反If it rains tomorrowIf it rained/should rain /were to rain虚拟条件句中的省略与倒装虚拟条件句中的省略与倒装在虚拟条件句中有在虚拟条件句中有were, had, should三个助动三个助动词中的一个时词中的一个时,可以省略可以省略if, 把这些词放在主语前。把这些词放在主语前。例如：If I should meet her, I would tell her.=Should I meet her, I would tell her.If I were in your positio

17、n,I would do it better.=Were I in your position,I would do it better.If they had made preparations,they would have succeeded=Had they made preparations, they would have succeeded. 1.If you had finished writing the book last month , it would be published next month.2.You would be much better now if y

18、ou had taken my advice.错综时间虚拟条件句错综时间虚拟条件句3. If you had met him yesterday, you would know what to do now. 有时假设的情况并不以条件从句表示出来，而是通过一个介词来表示或通过上下文或其他方式表示 如“but for ”，“without ”及“but that ” “ except for和“supposing ” “otherwise等表示含蓄的虚拟： But for your help,I would have failed. Without the money,I would not b

19、e alive now. （3）含蓄虚拟条件句）含蓄虚拟条件句 Supposing there were no gravity, objects would not fall to the ground when dropped. She wasnt feeling very well. Otherwise she wouldnt have left the meeting so early.She would leave her husband except for children.如果没有孩子的话如果没有孩子的话,她就会离开她的丈夫的她就会离开她的丈夫的2.without,otherwi

20、se和和but for 构成虚拟构成虚拟:含蓄含蓄条件句（条件句（but for要不是）要不是）Without sunlight, peoples life would be different from today.But for your help, I wouldnt have finished the work. Without your help, I would have failed.But for water, it would be impossible to live in the desert.5.Its (about/high) time +that -should +

21、V.过去时你该走了。我们该睡觉了。Its high time that you went.Its high time that you were going.Its high time that you should go.Its time that we went to bed.Its time that we should go to bed. 8. Its necessary /strange/ natural/ 8. Its necessary /strange/ natural/ important + that- important + that- 从句中的动词要用从句中的动词要用

22、虚拟，即（虚拟，即（shouldshould）+ +动词原形动词原形 It is important that we ( should ) It is important that we ( should ) master a foreign language.master a foreign language. It is strange that she refuse to come It is strange that she refuse to come to the party.to the party. Its necessary that we should study Its

23、necessary that we should study hard.hard.9. 某些简单句的固定句型：某些简单句的固定句型： Heaven help him! God bless you! May you succeed! Long live the Peoples Republic of China!高考链接:1. I didnt see your sister at the meeting. If she , she would have met my brother. A. has come B. did come C. came D. had come (MET94) 2. W

24、hen a pencil is partly in a glass of water, it looks as if it . A. breaks B. has broken C. were broken D. had been broken (MET95)3. You didnt let me drive. If we in turn, you so tired.A. drove ; didnt get B. drove ; wouldnt getC. were driving ;wouldnt get D. had driven ; wouldnt have got (MET95)4.Wi

25、thout the air to hold some of the suns heat, the earth at night ,too cold for us to live.A. would be freezing cold B. will be freezing coldlyC. would be frozen cold D. can freeze coldly(上海97)DCDA5._ it rain tomorrow, we would have to put off the meeting. A. Were B. Should C. Would D. Will (上海上海94)6.

26、 Janes pale face suggested that she _ ill, and her parents suggested that she a medical examination.A. be; should have B. was; have C. should be; had D. was; has (上海上海94)7._ for the free tickets, I wouldnt have gone to the films so often.A. If it is not B. Were it notC. Had it not been D. If they we

27、re not(上海上海95)8.Yesterday Jane walked away from the discussion. Otherwise, she _something.A. had said B. said C. might say D. might have said(上海上海96)BBCD 1.If I had had enough time, I my work. A.would finish B.must have finished C.would have finished D.had finished 2.Ten minutes earlier, they the pl

28、ane. A.will catch B.would catch C.would have caught D.will have caught 3.Mr Green requires that the students a composition every other week. A.write B.writen C.would write D.will write 4.Had he studied hard, he the exam. A.would pass B.could pass C.had passed D.would have passed5.I wish I what is ha

29、ppening there in his room.A.know B.known C.knew D.should know6.It is important that you sports every day.A.have B.would have C.must have D.will have7.If there were no water in the world, everything . A.will die B.would die C.would have died D.would have been dead8. what was going to happen ,I would

30、never have left her alone. A.Had I knownB.If I know C.If I knew D.If had I known9.He ordered that the work right away. A.should finish B.finished C.would be finished D.be finished10.Shall we go to the movie tonight? No, Id rather at home with our baby. Youd better not leave it to the babysitter at night.A.you stayed B.you sta