語法結構虛擬語氣

1、語法結構：虛擬語氣虛擬語氣是英語三級考試的必考知識點之一，也是體現(xiàn)英漢語言習慣區(qū)別的一個語法現(xiàn)象。在漢語里表示假設虛擬的情況常用一些虛詞來表示，例如“假設”、“如果”等等；而英文中表示虛擬的情況不但有虛詞的提示，謂語動詞也要相應的變化。虛擬語氣的基本作用是：1. 表達假設的情況，與事實相反；2. 表達異想天開很難實現(xiàn)的愿望；3. 表達建議、命令、勸告等語氣。本節(jié)重在講解if引導的虛擬條件句， 含蓄條件句，特殊結構中的虛擬語氣，以及should+動詞原形的用法。 一、虛擬語氣的基本形式和用法虛擬(條件)語氣中，主句與從句中謂語動詞的形式可分為下面三類：假設類型條件從句謂語動詞形式主句謂語動詞形式

2、與現(xiàn)在事實相反If+動詞的過去式(be用were而不用was)would(第一人稱可用should)+動詞原形與過去事實相反If+had+-ed分詞would(第一人稱可用should)+have+-ed分詞與將來事實可能相反If+were to+動詞原形或If+should+動詞原形would(第一人稱可用should)+動詞原形下面我們列舉近年的真題來強化記憶。例(1)Mary said to me, "Had I seen your bag, I _ it to you."A. will returnB. must returnC. could returnD. wo

3、uld have returned(【答案】D)(2004年4月45題)例(2)I would ask George to lend us the money if I _ him.A. had knownB. have knownC. knewD. know(【答案】C)(1995年38題)例(3)If Bob_ with us; he would have had a good time.A. would comeB. would have comeC. had comeD. came(【答案】C)(1995年59題)二、省略if的虛擬形式在虛擬條件句中，如謂語包含were，had，sho

4、uld等詞，則可以把這些詞放到主語前面，省略if。例(1)_ the advice of his friends, he would not have suffered such a heavy loss in his business.A. If he tookB. If he should takeC. Were he to takeD. Had he taken (【答案】D)(2004年4月32題)例(2)_, I should ask them some questions.A. Should they come to usB. If they come to usC. Were t

5、hey come to usD. Had they come to us(【答案】A)(1997年30題)例(3)_ you were busy, I wouldn't have bothered you with my questions.A. If I realizedB. Had I realizedC. Did I have realized thatD. As I realized(【答案】B)(1996年39題)三、含蓄條件句有時一個假設的情況不用條件從句表示，而用其它方式來表示，這樣的句子叫含蓄條件句。常用with，without，but for。例(1)Without

6、heat and sunlight, plants on the earth _ well. A. would not growB. will not grow C. had not grownD. would not be grown (【答案】A)(2004年11月32題)例(2)But for my classmates' help, I _ the work in time.A. did not finishB. could not finishC. will not finishD. would not have finished (【答案】D)(2004年4月36題)例(3

7、)But for the rain, we _ a nice holiday.A. should haveB. would have hadC. would haveD. will have had(【答案】B)(2003年4月28題)四、特殊詞或結構中的虛擬語氣： 以wish(that)引導的表示“愿望”的賓語從句wish后的賓語從句中要用虛擬語氣，而在虛擬語氣中時態(tài)的應用類似在非真實條件中從句時態(tài)的應用。表示現(xiàn)在或將來的愿望用：主語wish 從句(主語過去時)；表示一個過去沒有實現(xiàn)的愿望用：主語wish +從句(主語過去完成時)；例(1)I didnt go to the party, b

8、ut I do wish I _ there.A. wereB. would beC. had beenD. will be(【答案】C)(2001年53題)例(2)Peter wishes that he _ law instead of literature when he was in college.A. could studyB. studiedC. had studiedD. would study(【答案】C)(2000年53題) if only +句子(過去時/過去完成時)“要是就好了”If only 后面的句子如果是對現(xiàn)在或將來情況的虛擬，用過去時did ；如果是對過去情況的

9、虛擬，用過去完成時had done . 要注意與if 區(qū)別，if 只表示假設，“如果”，用真實語氣；而if only 表示不可能實現(xiàn)的情況，用虛擬語氣。例如：If only the alarm clock had rung. 當時鬧鐘響就好了。(對過去虛擬)If only I were rich. 要是我富有就好了。(對現(xiàn)在虛擬) would rather句子(過去時)表示寧愿、寧可的意愿，語氣比較婉轉。后接過去式。例(1)I am too busy these days. I would rather all of you _ next month for a dinner.A. comeB

10、. would comeC. came D. have come(【答案】C)(2002年46題)例(2)Id _ you didnt touch that, if you dont mind.A. rather B. better C. happierD. further(【答案】A)(1998年45題) it is time(that)，it is high time (that)句型中，謂語動詞用過去時，表示早該做而未做的事，意思是該了、早該了.例(1)Let's finish our homework in a few seconds; it's time we _.A

11、. played footballB. will play footballC. play footballD. are playing football(【答案】A)(2004年11月43題)例(2)Dont you think it is time you _ smoking?A. give upB. gave upC. would give upD. should give up(【答案】B)(1999年31題) 以as if，as though引導的從句在as if，as though引導的從句中，如果談論的是不可能或不真實的情況時，它們所引用的狀語從句要用虛擬語氣，動詞形式和wish

12、后面的從句動詞形式變化相同。例：He talks as if he _ everything in the world.A. knowsB. knewC. had knownD. would have known(【答案】B。本句表示說話人對現(xiàn)在的情況有所懷疑，所以用過去時。)五、should+動詞原形及should的省略(1)、一些表示建議、要求、命令等的動詞本身隱含說話者主觀的意見。因此這些動詞(或其變形，如名詞，形容詞，分詞等)后面的從句應使用虛擬語氣，即“should do”結構，其中的“should”常被省略。如：表“提議、建議”的動詞：suggest ,advise, propos

13、e, recommend, move(提議);表“要求、主張”的動詞：insist, require, request, demand , desire ;表“命令”的動詞：order, command. 例(1)I dont think it advisable that Tom _ to the job since he has no experience.A. be assigned B. is assigned C. will be assigned D. has been assigned(【答案】A)(2006年11月29題)例(2)His mother insisted that

14、 he _ the coat when going out.A. put onB. puts onC. to putD. putting on(【答案】A)(1999年58題)此處省略了should.例(3)The doctor advised that Mr. Malan _ an operation right away so as to save his life.A. had B. would have C. have D. was going to have(【答案】C)(1998年28題)此處省略了should.(2)、It is necessary/important/essen

15、tial/ vital/urgent / surprising/ amazing that引導的主語從句中，從句的謂語動詞要用should+原形動詞，should也可以省略。此類形容詞的特點是表示重要性或吃驚。例(1)it is vital that enough money_collected to get the project started. A. is B. be C must be D can be (【答案】B)(2004年11月24題)例(2)Its urgent that a meeting _ before the final decision is made.A. wil

16、l be arrangedB. must be arrangedC. be arrangedD. would be arranged(【答案】C)(2003年4月45題)(3)、以in case, lest, for fear that引起的狀語從句，表示“以防，以免”。其形式為should+動詞原形。如：He took his raincoat with him in case it should rain.他把雨衣帶在身上以防下雨。1.3配套練習1. You didnt let me drive. If we _ in turn, you_ so tired.A. drove; didnt

17、 B. drove; wouldnt getC. were driving; wouldnt get D. had driven; wouldnt have got 2. _, we could not have finished the work on time.A. If they do not help us B. Was it not for their helpC. Should they offer to help us D. But for their help3. _ today, he would get there by Friday.A. Was he leaving B

18、. If he is leaving C. Were he to leave D. If he leaves 4. If only I _ how to operate a computer as you do!A. had known B. would know C. should know D. knew5. When 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 broken6. The chairman requ

19、ested that_A. the members studied the problem more carefullyB. the problems were more carefully studiedC. the problems could be studied with more careD. the members study the problem more carefully7. If I _ you, I _ more attention to English idioms and phrases.A. was; shall pay B. am; will payC. wou

20、ld be; would pay D. were; would pay8. We cannot imagine what our world _ like without electric power.A. is B. will be C. would be D. were9. There was a half smile on his face which suggested that he _ happy to have given his life for his country.A. was B. should be C. would be D. were10. We all agre

21、ed to her suggestion that we _ to the Great Wall for sightseeing.A. will go B. go C. shall go D. should have gone11. The young man insisted that he _ nothing wrong and _ free.A. did; set B. had done; should be set C. do; be set D. had done; must be set12. I lost your address, otherwise I _ you long

22、before.A. had visited B. have visitedC. would have visited D. should visit13._the rain we would have had a nice holiday.A. But thatB. But forC. DespiteD. In spite of14_no gravity, there would be no air around the earth.A. Were thereB. There wereC. Was thereD. There be15. Its getting rather late. Its time we_.A. are goingB. wentC. goD. must go16. They keep telling us that it is vital that we _there on time.A. areB. beC. must beD. would be答案與解析1. 本句是對過去情況的虛擬。意為：如果我們輪流開車的話，你就不會那么累了。對過去虛擬，if條件句用過去完成式，had driven，主句用wouldnt have got。選D2. 選D。 這里是含蓄虛擬語氣用法。這句話的意思是：要不是他們幫忙，我們不會按時完成工作的。3. 選C。這是考