1、1語法要點虛擬語氣Subjunctive Mood2I.什么是語氣？語氣是動詞的一種形式，用以表示說話人對某種言行或某種事情的看法或態(tài)度。英語有三種語氣：陳述語氣，祈使語氣和虛擬語氣。陳述語氣一般用來講述事實或提出疑問。常常用于陳述句、疑問句和感嘆句。 e.g. I took a shower after supper. What are you going to do? What a beautiful flower!3 祈使語氣主要用于祈使句。 e.g. Get out of here!虛擬語氣4II. 什么是虛擬語氣？虛擬語氣是一種特殊的動詞形式，表示說話人所說的話不是事實，而是想象、假

2、設、建議、打算、意見、愿望、懷疑、推測、喜悅等等。 e.g. If we had met her last night, we would have told her what had happened. 如果我們昨晚見到她，我們就會告訴她發(fā)生了什么事。 （實際上，我們并沒有見到她，也沒有告訴她所發(fā)生的事。）5為什么要學習虛擬語氣？虛擬語氣是四級考試中重點考察的語法點。歷年四級考試中，僅僅單項填空部分就一共出現了48道虛擬語氣的題目！6II. 虛擬語氣的最基本形式 非真實性條件句是虛擬語氣最基本的表現形式。i. 由“if” 來引導的非真實條件句 組成方式： 非真實的條件從句 + 假設結果（主句

3、）7最基本形式的表達方式種類種類 從句的動詞形式從句的動詞形式 主句的動詞形式主句的動詞形式與現在事實相反與現在事實相反 動詞過去式動詞過去式 would/should/would/should/ （bebe的過去式常用的過去式常用 might/could +might/could + were were有時第三人有時第三人 動詞原形動詞原形 稱單數可用稱單數可用was)was)與過去事實相反與過去事實相反had+had+過去分詞過去分詞 would/should/would/should/ might/could + might/could + have + have + 過去分詞過去分詞與

4、將來事實相反與將來事實相反 1.1.動詞過去式動詞過去式 would/should/would/should/ 2.should+ 2.should+動詞原形動詞原形 might/could +might/could + 3.were to+ 3.were to+動詞原形動詞原形 動詞原形動詞原形8注意在主句中，should一般只與第一人稱搭配，could和might各人稱都可以使用，但would是最普遍，最常見的。9Examples 如果他在這里，他就會幫助我們。 If he were here, he would help us.如果昨天沒下雨，我們就去踢足球了。 If it had no

5、t rained yesterday, we would have played football.如果敵人膽敢襲擊我們，我們將把他們全消滅。 If the enemy were to (should) attack us,we would wipe them out completely.10實戰(zhàn)練習 1例：1995年6月四級第46題We didnt know his telephone number, otherwise we _ him,A) would have telephoned B) must have telephoned C) would telephone D) had t

6、elephoned 11解題思路本題是與過去時相反的虛擬句，從句中用過去完成式，主句中用would have done。本句相當于If we had known his telephone number，we would have telephoned him。答案是A) would have telephoned。12實戰(zhàn)練習 2例：1996年1月四級第44題Jean doesnt want to work right away because she thinks that if she _ a job she probably wouldnt be able to see her fri

7、ends very often.A. has to get B. had got C. were to get D. could have got13解題思路本句的意思是：“瓊不想馬上就工作，她認為要是找了工作，就不能經常探訪她的朋友了”。 這說明，瓊目前沒有工作。句中假設的情況在近期內并不會存在。該條件句應當用表示將來情況的虛擬語氣。 條件從句的謂語用should或were to引出。 因此C. were to get 是本題答案。選項A. has to get是陳述語氣的現在時，不能用于虛擬條件句中。選項B. had got是虛擬語氣的過去時，不能表示將來時間。選項D. could hav

8、e got不能用于虛擬語氣的條件從句中。14ii. 錯綜時間條件句有時虛擬條件從句表示的動作和主句發(fā)生的動作在時間上不一致。例如，一個與過去事實相反，另一個與現在事實相反。這種句子可稱為錯綜時間條件句。這時，謂語動詞的形式要根據各自表示的時間來調整。 e.g. If he were alive now, he might have finished his scientific researches on the bridge building three years ago. 如果他現在還活著，他可能三年前就完成了他的橋梁建筑科研工作了。15More examples要是昨天不下雪的話，我們

9、現在就應該在去上海的路上了。 If it had not snowed yesterday, we would be on the way to Shanghai.要是昨天晚上醫(yī)生來晚了的話，他今天就沒命了。 If the doctor had not come sooner last night, he would be dead today.16實戰(zhàn)練習 31999年一月四級題： If I hadnt stood under the ladder to catch you when you fell, you now. A. wouldnt be smiling B. wont smile

10、 C. couldnt have smiled D. didnt smile17解題思路這是一道錯綜時間虛擬條件句。在本句中，從句是對過去發(fā)生的事情進行假設，主句是對現在情況的假設。譯文：當你掉下來時，如果不是我在梯子下面把你接住，恐怕你現在就不會笑了。選A18實戰(zhàn)練習 2If you had taken your medicine yesterday, you _ well now.A. areB. had beenC. would beD. were正確答案正確答案: C19iii. 虛擬語氣的倒裝省略“if”的條件句考試重點最常見的形式：“if”引導的條件句但是，我們經?？梢钥吹健癷f”

11、被省略掉而把were, had, should, could放在主語前面的條件句。這種句型與“if”引導的條件句在表達意思上無任何區(qū)別。只是這種句型主要用于書面語。20A case in PointP. 37 (l. 28) in College English II. Unit 3 Were it left to me to decide whether we should have a government without newspapers or newspapers without a government, I should not hesitate a moment to pre

12、fer the latter.= If it were left to me to decide21倒裝虛擬語氣的用法如果條件從句中含有were, had, should或could, 可以省略連詞if, 把這些詞放在主語之前構成倒裝句。 e.g. 假如我是你的話，我課后就多做練習。 Were I (= If I were) you, I would do more exercises after class22注意！如果條件從句是否定式，倒裝時只能把not 放在主語之后，不能用縮寫式把not 放在主語之前。 e.g. Had you not told me about the matter,

13、 I should never have known the whole thing. (不能說：Hadnt you told me)23實戰(zhàn)練習 4例：1997年6月四級第42題：Had he worked harder, he _ the exams.A. must have got through B. would have got throughC. would get through D. could get through24解題思路本題前半句是表示與過去事實相反的虛擬條件從句，后半句是表示與過去事實相反的主句。相當于：If he had worked harder, he wou

14、ld have got through the exams.本題的答案是B. would have got through。選項A. must have got through（肯定通過）表示一種對過去事情的主觀推測，不是與過去事情相反的情況。另外，must不能用在虛擬條件句中。選項C. 和D. would / could get through（就會通過）是虛擬語氣現在時的一種表示方法，表示與現在事實相反。25iiii.含蓄虛擬條件句在虛擬語氣中，有的句子可能沒有明顯的由“if”引導的條件從句，但是，仔細一分析就會發(fā)現句子中隱含著一個條件，這種句子稱為含蓄條件句含蓄的條件可以用下列方式來表達

15、：（1）介詞或介詞短語 常見的有：but for（要不是）, with, without, in that position（在那個位置）, in the absence of（沒有）, under, in, for the fear of26 e.g. But for your help, we couldnt have succeeded in the experiment. = If it had not been for your help, 如果沒有你的幫助，我們的實驗不會成功。 沒有空氣就不會有風和雨Without air, there would be no wind or ra

16、in. = If there were no air, 如果條件更好一些，我們會做得更好。 Under a better condition, we would have done much better. 27(2) 連接詞常見的可以用來引導虛擬語氣的連接詞有:and, but, but that, or, or else, other, otherwise(否則)等。e.g. Im really busy; otherwise, I would certainly go with you. =if I werent so busy 28要不是由于交通事故，我就不會上課遲到了。（我本來上課不

17、會遲到的，可是發(fā)生了交通事故）。I would not have been late for class but there was a terrible traffic accident. 我本來可以寫信給你的，可我沒有時間。I would have written to you, but there was no time. = If there had been time, I would have written to you.29實戰(zhàn)練習 52001年1月大學英語四級題目：Some women a good salary in a job instead of staying hom

18、e, but they decided not to work for the sake of the family. A. must makeB. should have made C. would makeD. could have made 30解題思路本題涉及由but引導的暗含虛擬語氣的用法。我們從but后的陳述句中的謂語動詞“decided”中可看出，這是對過去情況的假設。因此but前面主句中的謂語動詞用虛擬語氣，其形式為：情態(tài)動詞 “should (ought to, could, might) + have done”，表示該動作本來應該發(fā)生而實際未發(fā)生。答案是D譯文：如果不呆在

19、家里，有些婦女本可獲得可觀的薪水，但是為了家庭，她們才不去工作。31III. 虛擬語氣的特殊形式虛擬語氣的特殊形式是這一語法項目的難點。說它難是因為從邏輯思維和語言使用習慣上同漢語沒有明顯的聯系。但是這種特殊形式在四級考試中出現的頻率非常高。它的表達方式有如下幾個方面：32i. 虛擬語氣在 as if, as though, 等引導的從句中的應用As if, as though可以用來引導狀語從句或表語從句，表示猜測，假定，聯想等等。虛擬語氣在as if, as though引導的從句中的表現方式大致有三種：(a) 動詞的過去時(b) had + 過去分詞(C) would （或might)

20、+ 動詞原形33e.g. He talks as if he knew all about it. 他談起來好象全知道似的。 我記得整件事情，好象就發(fā)生在昨天似的。 I remember the whole thing as if it happened yesterday. She cried as if her heart would break. as if, as though引導的從句中謂語動詞可以用陳述語氣，這特別是當表示的情況是真實的，或實現的可能性較大的時候。 She looks as if she were sick. (實際上沒有?。?She looks as if she

21、 is sick. (實際上可能或的確是病了）34ii.虛擬語氣在主語從句中的運用在“It is + 某些形容詞（或過去分詞）+主語從句”的句型中，主語從句中的動詞形式用“should + 動詞原形 （should可以省略）”。常用的形容詞有：necessary, important, essential, obligatory, vital, impossible, strange, urgent, desirable, natural, advisable, preferable等等常用的過去分詞通常是表示提議、要求、命令等動詞的過去分詞。例如：decided, arranged, sug

22、gested, required, demanded, urged, proposed, recommended, ordered, desired, advised35e.g. It is advisable that a general announcement be made to the staff. 最好給全體人員發(fā)個通知。 需要給這臺機器加潤滑油了。 It is required that the machine (should) be oiled.已決定推遲會議。 It has been decided that the meeting (should) be put off.3

23、6實戰(zhàn)練習 6CET-4, 1996. 1.It is politely required by the hotel management that radios after 11 oclock at night. A. were not playedB. not be playedC. not to playD. did not play37解題思路本題涉及主語從句中的虛擬語氣用法。在 It is required / demanded/+ that 從句結構中，從句中謂語動詞都要用虛擬語氣，其形式為(should) + 動詞原形（should可以省略）。因為收音機是“被放的”，要用被動，因

24、此選B.38實戰(zhàn)練習 It is necessary that an efficient worker _ his work on time.wfinisheswcan finishwfinishwhas finishedA.答案答案: C39iii. 虛擬語氣在賓語從句中的應用在表示提議、要求、命令、意志等動詞之后的賓語從句中，可以用 “should + 動詞原形（should可以省略）”形式做謂語。這類動詞有：advise, ask, beg, determine, require, suggest, request, demand, urge, propose, command, des

25、ire, insist, prefer, order, pray, recommend 等等40e.g. She insisted that the seat (should) be booked in advance. 她堅持要預定座位。 他們要求他唱支歌。 They requested that he (should) sing a song. 我建議推遲會議。 I suggest that the meeting (should) be put off.41實戰(zhàn)練習 7CET-4, 1993. 6We desire that the tour leader us immediately

26、of any change in plans.A. informB. informedC. informsD. has informedA42iv. 虛擬語氣在表語從句、同位語從句中的應用在demand, motion, idea, proposal, suggestion, order, recommendation, requirement, decision, advice等表提議、要求、命令等名詞之后的表語從句、同位語從句中，謂語動詞可用“should + 動詞原形 （should可以省略) ”形式。43e.g. He issued the order that the troops

27、(should) withdraw at once. 他命令部隊馬上撤退。 我的建議是我們派幾個同志去幫助別的小組。 My suggestion is that we (should) senda few comrades to help the other groups. 他發(fā)出命令要求立即完成這項工作。 He gave the order that the work be done at once.44實戰(zhàn)練習 8CET-4，2000. 6The suggestion that the mayor the prizes was accepted by everyone.A. would p

28、resentB. presentC. ought to presentD. presents B45v. wish之后賓語從句中動詞的三種形式動詞wish后面的賓語從句，表示不可能實現的愿望，其動詞形式有三種：與現在事實相反從句動詞用過去時與過去事實相反 從句動詞形式 “had+過去分詞”與將來事實可能相反 從句動詞用或不可能實現的愿望 “would或could + 動詞原形”形式46我要是記得她的地址就好了。 I wish I remembered her address. 我們真希望你來參加我們的新年聯歡會。 （但你沒來） We wish you had come to our New Y

29、ears party. “Ill be back before Christmas.” “I wish youd come back before Thanksgiving.”47實戰(zhàn)練習 9CET-4，2001. 6Jack wishes that he business instead of history when he was in university.A. studiedB. had been studyingC. studyD. had studiedD48vi. 虛擬語氣在if only引導的從句中的應用 在if only引導的從句中，謂語動詞要用虛擬語氣，其用法與wish后賓

30、語從句的用法基本相同，表示“但愿，要是就好了”之意。If only I knew what you wanted. 要是我知道你需要什么就好了他要是準時到達就好了，那樣就不會被處分了。 If only he had arrived in time, he would not have been punished.49實戰(zhàn)練習 10CET-4，1997. 1If only the committee the regulations and put them into effect as soon as possible.A. approveB. can approveC. will approveD. would approveD50vii. 虛擬語氣在“its (hig