英語中的虛擬語氣是四、六級(jí)考試的必考考點(diǎn)。如果你掌握了以下十八個(gè)例句，再做好文后所配的練習(xí)，虛擬語氣難題就可以迎刃而解了。
一、虛擬語氣在條件從句中的用法
(一)形式
略
注：
1.在從句中，be動(dòng)詞多用were的形式。在口語中，如果主語是第一、第三人稱單數(shù)的話，be動(dòng)詞可用was，但人們總是說：If I were you...
2.主句中的謂語可以由would，should，could和 might這四個(gè)不同的情態(tài)動(dòng)詞來構(gòu)成。
3.與將來事實(shí)相反的條件從句中，謂語有三種不同的形式：過去式、were +to do或should +do。
例句1：If I were you，I would study hard.我要是你的話，我就會(huì)好好學(xué)習(xí)。(與現(xiàn)在事實(shí)相反)
例句2：If I had studied hard，I would have passed CET-6 last semester.我要是早就好好學(xué)習(xí)的話，那么我上個(gè)學(xué)期就通過六級(jí)考試了。(與過去事實(shí)相反)
例句3：If Iwere to pass CET-6，I would treat you to dinner at KFC.我要是過了六級(jí)考試，就請(qǐng)你去吃肯德基。(與將來事實(shí)相反)
(二)省略/倒裝
如果在虛擬從句中包含有一個(gè)助動(dòng)詞、情態(tài)動(dòng)詞、動(dòng)詞be或have，則可把if省略，把上類動(dòng)詞提到主語之前，使用倒裝語序。
例句4：Had it not been for the PLA，we wouldn’t have been able to beat the flood.4要不是人民解放軍，我們是無法戰(zhàn)勝洪水的。
例句5：Were he here now，he would certainly help me.5他要是在這里肯定會(huì)幫我的忙。
注4：例句4中的從句部分出現(xiàn)了否定詞not，如果把該句還原成正常語序，應(yīng)該是：
If it hadn’t been for the PLA，we wouldn’t have been able to beat the flood.
但是一旦句子發(fā)生了省略，就必須把hadn’t分開，否定詞not還原，放在主語之后，不可寫成Hadn’t it been for的形式。
注5：在虛擬條件從句中，動(dòng)詞be在正常語序中常用were，在口語中，當(dāng)主語是第一、第三人稱單數(shù)時(shí)，可用was，但在if的倒裝句中，必須用were。
(三)錯(cuò)綜時(shí)間條件句
有時(shí)，從句和主句中所表示的動(dòng)作發(fā)生的時(shí)間是不一致的，這時(shí)就要根據(jù)其所表示的時(shí)間來進(jìn)行調(diào)整。
例句6：If I were you，I would have gone to see the doctor.我要是你，我早就去看病了。(從句與現(xiàn)在事實(shí)相反，主句與過去事實(shí)相反)
例句7：If you had gone to see the doctor，you would be all right now.你要早去看病，你現(xiàn)在就沒事了。(從句與過去事實(shí)相反，主句與現(xiàn)在事實(shí)相反)
(四)含蓄條件句
虛擬的條件有時(shí)可以不用條件從句來表示，而是通過某些介詞短語來表達(dá)。
例句8：But for the English test，I would have gone home this week.6要不是英語測試，我這個(gè)禮拜就回家了。
注6：除了but for(要不是)以外，能夠表示虛擬條件的詞和短語還包括：but that(要不是)、without(沒有)、otherwise(否則)、or(不然)、under...circumstances(在……的情況下)、in the past(在過去)等等。
過級(jí)考試真題
1.He must have had an accident，or he then.
A.would have been here B.had to be here
C.should be here D.would be here
2.It was essential that the application forms back before the deadline.
A.must be sent B.would be sent C.be sent D.were sent
3.We desire that the tour leader us immediately of any change in plans.
A.inform B.informs C.informed D.has informed
4.Look at the terrible situation I am in!If only I your advice.
A.follow B.had followed C.would follow D.have followed
5.It is recommended that the project until all the preparations have been made.
A.is not started B.will not be started
C.not be started D.is not to be started
6.I wish I longer this morning，but I had to get up and come to class.
A.could have slept B.slept C.might have slept D.have slept
7.We didn’t know his telephone number;otherwise we him.
A.would have telephoned B.must have telephoned C.would telephone D.had telephoned
8.The story written by the famous writer is as real as if it only yesterday.
A.happened B.had happened C.was happening D.happen
9.It is necessary that a good engineer a basic training in general science.
A.be given B.is given C.will be given D.was given
10.I suggested that the students each a plan for the summer vacation.
A.would make B.make C.will make D.made
11.She said she’d rather he tomorrow instead of today.
A.comes B.will come C.had come D.came
12.I’d lend you my bicycle I could remember who last used it.
A.except that B.if only C.on condition that D.considering that
13.It is politely requested by the hotel management that radios after 11o’clock.
A.were not played B.not to play C.not be played D.did not play
14.Jean doesn’t want to work right away because she thinks that if she a job she probably wouldn’t be able to see her friends very often.
A.has to get B.were to get C.had got D.could have got
15. before we depart the day after tomorrow，we should have a wonderful dinner party.
A.Had they arrived B.Would they arrive C.Were they arriving D.Were they to arrive
16.It is important that enough money to fund the project.
A.be collected B.must be collected C.was collected D.can be collected
17.If only the committee the regulations and put them into effect as soon as possible.
A.approve B.will approve C.can approve D.would approve
18.Had he worked harder，he the exams.
A.must have got through B.would have got through
C.would get through D.could get through
19.I don’t think it advisable that Tom to the job since he has no experience.
A.is assigned B.will be assigned
C.be assigned D.has been assigned
二、虛擬語氣在其他從句中的用法
(一)賓語從句
1.wish后的賓語從句
例句9：I wish I were as young as you.7我希望自己像你一樣年輕。
注7：wish從句后使用虛擬語氣時(shí)，動(dòng)詞的形式根據(jù)所表示的時(shí)間概念而采用不同形式：過去時(shí)(與現(xiàn)在相反)、過去完成時(shí)(與過去事實(shí)相反)或過去將來時(shí)(與將來事實(shí)相反)。
2.would rather和would sooner后的賓語從句
兩個(gè)詞組都表示寧愿、寧可的意思，后面如用賓語從句，動(dòng)詞采用過去時(shí)(與現(xiàn)在或?qū)硎聦?shí)相反)或過去完成時(shí)(與過去事實(shí)相反)。
例句10：I’d rather I hadn’t met you.8我寧愿從來就沒遇見過你。
注8：would rather和would sooner兩詞組除了要掌握它們后面賓語從句中虛擬語氣的用法以外，還要知道這兩個(gè)詞組后面都可以直接加動(dòng)詞原形，這也是四、六級(jí)考試中的一大考點(diǎn)，如：美國歌曲《山鷹》中的第一句歌詞就是：I’d rather be asparrow than a snail.其中，就使用了句式would rather do than do(寧愿做……而不做……)。
3.suggest等動(dòng)詞后的賓語從句
表示主觀判斷、推測、建議、命令和要求的動(dòng)詞通常引起虛擬的賓語從句，此類動(dòng)詞后的賓語從句中采用should +do、should可以省略的虛擬語氣形式。該類動(dòng)詞包括：
(1)高中詞匯：advise(勸告)、ask(要求)、decide(決定)、insist(堅(jiān)持)、order(下令)、suggest(建議)等。
(2)四、六級(jí)常考詞匯：command(命令)、demand(要求)、desire(渴望)、propose(提議)、recommend(勸告)、require(要求)等。
(3)其他詞匯：consent(同意)、deserve(值得提
起)、maintain(主張)、move(提議)、urge(極力主張)、 vote(提議)等。
例句11：I recommend that you all be diligent if you want to pass the exam.如果你們要考及格，我勸你們勤奮學(xué)習(xí)。
(二)主語從句
在It is +形容詞/某些動(dòng)詞的過去分詞+主語從句的結(jié)構(gòu)中，從句的謂語動(dòng)詞須用動(dòng)詞原形或 should +do的形式。這些形容詞包括：
(1)高中詞匯：decided(決定的)、important(重要的)、ordered(命令的)等。
(2)四、六級(jí)常考詞匯：advisable(合理的)、demanded(要求的)、desired(期望的)、desirable(合乎需要的)、essential(緊要的)、insistent(堅(jiān)持的)、natural(自然的)、preferable(更可取的)、proposed(建議的)、 recommended(推薦的)、required(要求的)、urgent(緊迫的)、vital(極其重要的)等。
(3)其他詞匯：appropriate(適當(dāng)?shù)?、arranged(安排好的)、better(較好的)、imperative(迫切的)、possible(可能的)、probable(可能的)、resolved(決心的)、 strange(奇怪的)、suggested(建議的)等。
例句12：It is highly desirable that a new mayor be appointed for this city.這座城市急需任命一位新市長。
(三)表語從句和同位語從句
有些名詞引起的表語從句或同位語從句中，謂語動(dòng)詞須用動(dòng)詞原形或should +do的形式。這些名詞包括：advice(忠告)、decision(決定)、demand(要求)、desire(渴望)、idea(想法)、motion(提議)、necessity(必要性)、order(命令)、plan(計(jì)劃)、preference(偏愛)、proposal(建議)、recommendation(推薦)、requirement(要求)、suggestion(建議)等。
例句13：His proposal is that we turn off TVfor half an hour every day.他建議我們每天少看半個(gè)小時(shí)的電視。
特別提示：從以上的各類從句中我們可以得到以下的推論，即當(dāng)一個(gè)動(dòng)詞后面的賓語從句中要使用(should)+do的虛擬語氣形式時(shí)，則可推理出用法相同的一組從句。以動(dòng)詞advise為例：
(1)I advise that we stay and wait here.(動(dòng)詞后的賓語從句)
(2)It is advised that we stay here.(It is +動(dòng)詞的過去分詞+that引導(dǎo)的主語從句)
(3)It is advisable that we stay here.(It is +由該動(dòng)詞轉(zhuǎn)換的形容詞+that引導(dǎo)的主語從句)
(4)My advice is that we stay here.(由該動(dòng)詞轉(zhuǎn)換的名詞后的表語從句)
(5)I offered the advice that we stay here.(由該動(dòng)詞轉(zhuǎn)換的名詞后的同位語從句)
(6)I think it advisable that we stay here.(由該動(dòng)詞轉(zhuǎn)換的形容詞作賓語補(bǔ)足語，it為形式賓語，真正的賓語從句中使用虛擬語氣)
以上六類從句中所使用的都為(should)+do的虛擬語氣形式。
歷年MBA考題
20.If you had rung up the TV repairman，you the sports program.
A.could watch B.could be watching
C.could have watched D.could not watch
21.If you had taken your umbrella with you when you went to work this morning，you wet now.
A.will not be B.will not have been
C.would not be D.would not have been
22.If this university such a good reputation，I would not have come here.
A.didn’t have B.doesn’t have
C.would not be D.would not have been
23.She did not go to the North，instead she remained here in the South.The doctor suggested that she there.
A.not go B.go not C.couldn’t go D.didn’t go
24. ，call the police.
A.If anyone will attempt to break in
B.Would anyone attempt to break in
C.Anyone should attempt to break in
D.Should anyone attempt to break in
(四)狀語從句
1.as if/as though引導(dǎo)的狀語從句
as if/as though(仿佛、好像)引起方式狀語從句，從句中的虛擬語氣形式與wish后的賓語從句相同：
a.一般過去時(shí)(表示與現(xiàn)在事實(shí)相反)
b.過去完成時(shí)(表示與過去事實(shí)相反)
c.would +do(表示與將來事實(shí)相反)
例句14：You look as if you had seen a ghost.你看起來好像撞見鬼了。
2.lest/in case /for fear that引導(dǎo)的狀語從句
lest(以防、以免)、in case(萬一、以防)、for fear that(因恐、免得)引起的狀語從句中，謂語動(dòng)詞要使用(should)+do的形式。
例句15：The old woman walked slowly lest she(should)slip.老太太走得很慢，以免滑倒。
3.whoever等引導(dǎo)的狀語從句
由連接代詞whoever(無論誰)、whatever(無論什么)、whichever(無論哪個(gè))等和連接副詞however(無論如何)、whenever(無論何時(shí))、wherever(無論哪里)等及 no matter+how/what/when /where /who(無論怎樣/什么/何時(shí)/哪里/誰)構(gòu)成的詞組引導(dǎo)的讓步狀語從句，若表示說話人對(duì)現(xiàn)在或?qū)淼耐茰y，謂語動(dòng)詞常用虛擬語氣，形式為動(dòng)詞原形或may /might+do。
例句16：Whichever be the case，my situation remained the same.無論是哪種情況，我的處境都一樣。
(五)定語從句
It is time(是……時(shí)候了)，Itis about time(差不多是……時(shí)候了)，It is high time that(該……了)句式中，that引導(dǎo)的定語從句中用過去時(shí)表示虛擬。
例句17：It is time that we protected our environment.我們應(yīng)該保護(hù)我們的環(huán)境了。
三、虛擬語氣在表示祝愿的句子中的應(yīng)用
在if only或if...only(但愿、要是……就好了)引起的表示遺憾的感嘆句中，謂語動(dòng)詞使用虛擬語氣，形式為過去時(shí)。
例句18：If only I could see Jordan.我要是能見到喬丹就好了。
以上的十八句是筆者精心設(shè)計(jì)的，每一個(gè)句子都是虛擬語氣的一個(gè)考點(diǎn)，如果能夠把這十八句融會(huì)貫通，達(dá)到舉一反三的程度，虛擬語氣部分則可輕松過關(guān)。
歷年考研試題
25.There is a real possibility that these animals could be frightened， a sudden loud noise.
