虚拟语气虚拟语气，用来表达说话人的愿望、请求、虚拟语气，用来表达说话人的愿望、请求、意图建议、惊奇、设想等。而不表示客观存意图建议、惊奇、设想等。而不表示客观存在的事实。在的事实。I wish I were a bird.Look at those doves flying across the sky in the strong sunlight.I wish I were a white cloud giving them cool shade.If I were you,I shouldnt do it.虚拟语气在简单句中的用法虚拟语气用于简单句时，一般表示祝愿，命令等。谓语动词要用动词原形动词原形。1.表示祝愿：eg.Long live the Peoples Republic of China!May you be happy all your life!2.表示命令：eg.Everybody leave the room!Let one of you go and tell her to come.虚拟语气在主从复合句中的用法1.在条件状语条件状语从句中的用法：A.表示与现在事实现在事实相反的情况条件从句的动词形式条件从句的动词形式主句的动词形式主句的动词形式If I(we,you,he,she,it,they)+行为动词的行为动词的过去式（过去式（be的过去式的过去式一般用一般用were。在。在he,she,或或it等后，也可用等后，也可用was。）。）I(we,you,he,she,it,they)+should/would/might/could+动词原形动词原形If I had more time,I should study German.If she were(was)not so busy,she would attend the meeting this afternoon.If they didnt take the physical exercises every day,they wouldnt be so healthy.If you went to bed earlier,you would not be so sleepy in the morning.B.表示与过去事实过去事实相反的情况条件从句的动词形式条件从句的动词形式主句的动词形式主句的动词形式If I(we,you,he,she,it,they)+had+过去过去分词分词I(we,you,he,she,it,they)+should/would/might/could+have+过去过去分词分词If you had taken the old experienced workers advice,you wouldnt have failed in the experiment.I would have checked my paper again if I had had more time at yesterdays examination.He would have already recovered from his illness if he had seen the doctor in good time.C 表示与将来事实将来事实相反的情况条件从句的动词形式条件从句的动词形式主句的动词形式主句的动词形式1.If I(we,you,he,she,it,they)+行为动词过去式行为动词过去式(be的的过去式一般用过去式一般用were)通常要与通常要与一个表示将来的时间状语连用。一个表示将来的时间状语连用。2.If I(we,you,he,she,it,they)+should+动词原形。动词原形。3.If I(we,you,he,she,it,they)+were to+动词原形。动词原形。I(we,you,he,she,it,they)+should/could/might/would+动词原形动词原形If it rained tomorrow,our picnic would be put off.If I saw him tomorrow,I would pass your note to him.If it should rain tomorrow,our picnic would be put off.If it were to rain tomorrow,our picnic would be put off.She might come back and start off again the day after tomorrow if she were to miss the train tomorrow.注意注意：用虚拟语气表示条件从句，可以放在主用虚拟语气表示条件从句，可以放在主句之前，也可以放在主句之后，但所表达的意句之前，也可以放在主句之后，但所表达的意义侧重点不同。如主句在前，强调义侧重点不同。如主句在前，强调“结果结果”；如如从句在前，强调从句在前，强调“条件条件”。按汉语习惯，通常。按汉语习惯，通常条条件从句在前，主句在后。不论英文主从句的前件从句在前，主句在后。不论英文主从句的前后，汉语翻译不变。后，汉语翻译不变。2.在主语从句主语从句中的用法：通常由形式主语it引出的主语从句来表达虚拟语气。在主语从句中，谓语动词用should+动词原形，表示什么是必要，重要，奇怪等具体内容。It is necessary(important,natural,strange,essential,urgent,surprising)that we should clean the room every day.It is a pity(a shame,no wonder)that you should be so careless.should 意为应该，竟然，可以省去，但不可换成would。3.在某些欲望动词arrange,command,demand,desire,insist,order,propose,request,suggest,advice,prefer,agree,expert,intend,recommend,ask,decide,object,persist,determine等后面的宾语从句宾语从句用(should)+动词原型.We suggested that we should have a meeting.We insisted that they go with us.The doctor ordered that she stay in bed for a few days.He demanded that we should start right away.4.在It is(high,about)time that+宾语从句宾语从句中，从句的谓语动词用过去式，表示该做某事了 的意思，这也是一种虚拟语气。It is time we got up.(should get up)It is high time our athletes showed (should show)their best.It is time(that)we started.情态动词情态动词have+p.p.1.should/ought to+have done/have been doing 表示本来应该做某事却没有做表示本来应该做某事却没有做You should/ought to have asked my permission first.You shouldnt have been resting at that time of day.2.must+have+have done/have been doing 表示对过去事态的一种猜测（可对可错）表示对过去事态的一种猜测（可对可错）只用于肯只用于肯定句。否定句和疑问句需用定句。否定句和疑问句需用cant和和can.Her eyes are red.She must have been crying.You must have left your handbag in the theatre.3.may/might/can/could+have done/have been doing 表示过去的表示过去的”可能可能”She could have missed the train.might/could+have done/have been doing有时可以表示本来可能发生但没有发生，或者有时可以表示本来可能发生但没有发生，或者本来可能完成却没有完成的动作。本来可能完成却没有完成的动作。You might have killed yourself.I could have passed the examination,but I failed.Ex:1.The representative of the company demanded that part of the agreement _ revised.A.will be B.is C.to be D.be2.It is required that anyone applying for a drivers license _ a set of tests.A.take B.takes C.took D.will take3.Tom _the party as no one saw him there yesterday evening.A.cant attend B.mustnt attend C.Wont have attended D.couldnt have attendedDAD4.It is most desirable that he _ for the information by himself with a few clicks online.A.search B.searched C.has searched D.will search5.This ATM has been out of service for a few days.It should _ last week.A.fix B.be fixed C.have fixed D have been fixedAD6.The boy passed the final exams.But if he had spent more time on them,the results(be)_much better.7.If he had taken his lawyers advice,he(save)_himself a great deal of trouble.8.He might have been killed in that car accident yesterday if he(take)_ part in that activity with the team.would have beenwould have savedhad taken8.He might not have been killed in the traffic accident yesterday if he(fasten)_ the seat belt.9.It is important that he(be)_ called back immediately.10.It is required that every employee(come)_in their uniform before 8:30a.m.11.Jack must(go)_ away we cant find him anywhere in the factory.had fastenedbecomehave gone12.I