发给学生的讲解和练习(虚拟语气).doc

1虚拟语气用于条件状语从句(一般形式)虚拟语气一般表示不可能实现的愿望或者对既定事实的一种假设。 条件从句中的谓语动词的形式主句中的谓语动词的形式对现在虚拟动词过去式（be动词用were）should/would/could/might+动词原形对过去虚拟had+过去分词should/would/could/might + have+过去分词对将来虚拟1.动词过去式（be动词用were）should/would/could/might +动词原形2.should+动词原形should/would/could/might +动词原形3.were to+动词原形should/would/could/might +动词原形注意：（1）主句中的should通常用于第一人称，would, could, might可用于任何人称，同可根据意思选择合适的情态动词。(2)有时候，条件从句表示的动作和主句表示的动作，发生的时间是不一致的（如一个是过去发生的，一个是现在发生的）。这时，动词的形式要根据它所表示的时间来调整。If the weather had been more favorable, the crops would be growing still better.If you were in better health, we would have allowed you to join them in the work.If we hadnt got everything ready by now, we should be having a terrible time tomorrow.(3) 若if从句中省略if，则前提were/ had/ should ，把它们倒装放到主语之前：Were I in school again, I would work harder.Had you been here earlier, you would have seen him.Should there be a meeting tomorrow, I would come .2.虚拟语气用于宾语从句（1）“wish + 宾语从句”表示不能实现的愿望，“可惜/悔不该/但愿”从句中谓语动词形式一般退后一个时态：与现在事实相反：动词过去式与过去事实相反: had + done 或could(would)+have +done与将来事实相反： could/would/might + do 例如：I wish you told me earlier.We wish we had arrived there two hours earlier. I wish we could go to the seaside today/tomorrow（2）某些动词后的宾语从句中需用should+动词原形的虚拟语气形式，“should”可以省略。常见的动词有:坚持insist;命令order, command ;建议suggest , advise, propose, recommend;要求demand, request, require, ask, desire, urge; 另外有: prefer, decide, maintain注意: suggest表 “暗示”“表明” 时， insist表“坚持认为”时不用虚拟语气He ordered/demanded/suggested that the students (should) wash the clothes every week by themselves. Mike insisted that he had never stolen anything. Her pale face suggested that she was ill.3.虚拟语气用于表语从句/同位语从句.作advice / idea /order /demand /plan /proposal /suggestion /request/decision 等后面的表语从句和同位语从句，其谓语动词要用虚拟语气的结构“（ should ) + 动词原形” .例如：We all agreed to his suggestion that we (should) go to Beijing for sightseeing.My idea is that he (should) do exercises first.4. 虚拟语气用于主语从句。基本句型： (1). It be+过去分词+that+(should)+动词原形+过去分词：suggested, proposed, recommended, requested, ordered, desired, decided, required,demanded, etc.It is required that nobody (should) smoke here.Its suggested that everybody (should) buy a dictionary.(2). It be+形容词+that+(should)+动词原形+形容词:important, necessary, natural, appropriate, right, wrong, better, proper, funny, strange, surprisingdesirable (想要的), preferable(更可取的),better, advisable (明智的/合理的/适当的/可行的), essential,vital,probable,possible, strange , urgent（紧迫的）etc.It is necessary that we (should ) have a walk now.Its important that we (should) take good care of the patient.(3). It be+名词（advice，decision，desire，demand，idea，motion，order，pity，preference，proposal，recommendation，requirement，resolution，shame，suggestion，surprise，wish，wonder, a pity/a shame/ no wonder） that+ (should)+动词原形+注意(2)&(3): 这种从句表示的是事实。如果说话人对这种事实表示惊奇，就用虚拟语气。反之，如果不表示惊奇， that 从句也可用陈述语气。例如:It is strange that he did not come yesterday. It is a pity that you cant swim.5. 其它状语从句中的虚拟语气（1）虚拟语气用于以 as if / as though 引导的表语从句或状语从句.谓语动词的形式有三种，与上文的wish的用法完全相同。但as if /as though 后的从句也常用陈述语气，这是因为从句中的情况往往是可能发生的或可能被设想为真实的。例如：It looks as if our side is going to win.（2）用在lest, for fear that和in case引导的状语从句中，这时谓语动词用should+动词原形，should可以省略。She closed the windows lest she (should) catch a cold.6.虚拟语气的一些特殊句式（1） “It is (high/about ) time (that ) ”句型中，从句的谓语动词用过去式，或 should动词原形(should不能省略,be 用were来)表示，意为“（现在）该”It is time that I went and picked up my little girl from school.It is high time we were going.（2）if only 引导的感叹句：If only I had taken his advice. If only I were a bird.（3）If it were not for 此结构意为“如果没有”，表示与现在事实相反的假设If it had not been for “如果当时没有”，表示与过去事实相反的假设If it were not for the rain, the crops should /would die. (Were it not for the rain, )If it had not been for your timely help, I would have failed. (Had it not been for your,)（4）在would rather 后面的从句中：A.从句用过去时指现在。 B.从句用过去时指将来。C.从句用过去完成时指过去。例如 ：I would rather you paid me now. I would rather they came tomorrow.I would rather she hadnt done that.5)A.通过分词短语表达条件例如：Given more attention, the crops could have grown better.(=If they had been given more )B.用介词短语代替条件状语从句.例如:Without air, there would be no living things. I would not have succeeded but for your help.C. 情境中提供虚拟语气 Suppose 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.6)无词句暗示条件例如：Such mistakes could have been avoided. (暗含条件从句if we had been more careful.)It was so quiet that you could have heard a pin drop. (暗含条件从句if it had dropped to the ground.)虚拟语气练习 1.Everything _ if Albert hadnt called the fire brigade. a. will be destroyed b. will have been destroyed b. would be destroyed d. would have been destroyed 2.If you hadnt gone with Tom to the party last night,_. a. you would meet John already b. you wont have missed John c. you will have met John d. you would have met John 3.Supposing this ship _ , do you think there would be enough life jackets for all the passengers? a. was sinking b. has sunk c. were to sink d. sunk 4.The insects would devour all our crops, if _ for the protection we get from insect-eating animals. a. it is not b. it were not c. were it not d. they were not 5.The teacher suggested that each student _ a plan for the vacation. a. made b. make c. makes d. will make 6.Frankly, Id rather you _ anything about it for the time being. a. do b. dont do c. didnt do d. will not do 7. The business of each day, _ selling goods or shipping them, went quite smoothly. a. it being b. be it c. was it d. it was 8.The idea is that the nation _ an unmanned spacecraft to explore the planet first. a. sent b. sends c. send d. must send 9.Its high time you _. a. start to work b. would start to work c. started to work d. had started to work 10.“If I hadnt practiced when I was younger,” the musician says, “ I _ able to play so well now.” a. wouldnt be b. wont be c. wouldnt have been d. couldnt have been 11.It is essential that you _ there in person. a. are b. were c. be d. will be 12. Id just as soon _ to the theatre tonight. a. not going b. not to go c. not go d. that I wont go 13.We required that the machine parts _ cast iron（煅铁，铸铁）. a. is made of b. be made from c. be made of d. is made by 14.The manager urged that the cost of production _. a. to be further reduced b. was further reduced c. be further reduced d. should further reduced 15.The business is risky. But _ we would be rich. a. should we succeed b. we should succeed c. might we succeed d. would we succeed 16.I wish our teacher _ to give another test. I havent got prepared yet. a. isnt going b. werent going c. will not going d. could have gone 17.I wish I _ to the movies with you last night. a. went b. did go c. could go d. could have gone 18.Id just as soon _ rudely to her. a. that you wont speak b. your not speaking c. you not speak d. you didnt speak 19.If I _ in the twenty-first century, I _ my vacation in a very different way. a. should livewould spend b. will live .should spend c. are living should have spent d. will be livingwould have spent 20.It is required that the machine _ as frequently as necessary. a. be oiled b. must be oiled c. is oiled d. will oil 21.His English teacher recommends that he _ a regular degree program. a. begins b. begin c. will begin d. is beginning 22.We prefer that the plan _ before being put into execution. a. is fully discussed b. must be fully discussed c. be fully discussed d. will be fully discussed 23.What do you think of his proposal that improvem