英语中的虚拟语气是四、六级考试的必考考点。如果你掌握了以下十八个例句，再做好文后所配的练习，虚拟语气难题就可以迎刃而解了。
一、虚拟语气在条件从句中的用法
(一)形式
略
注：
1.在从句中，be动词多用were的形式。在口语中，如果主语是第一、第三人称单数的话，be动词可用was，但人们总是说：If I were you...
2.主句中的谓语可以由would，should，could和 might这四个不同的情态动词来构成。
3.与将来事实相反的条件从句中，谓语有三种不同的形式：过去式、were +to do或should +do。
例句1：If I were you，I would study hard.我要是你的话，我就会好好学习。(与现在事实相反)
例句2：If I had studied hard，I would have passed CET-6 last semester.我要是早就好好学习的话，那么我上个学期就通过六级考试了。(与过去事实相反)
例句3：If Iwere to pass CET-6，I would treat you to dinner at KFC.我要是过了六级考试，就请你去吃肯德基。(与将来事实相反)
(二)省略/倒装
如果在虚拟从句中包含有一个助动词、情态动词、动词be或have，则可把if省略，把上类动词提到主语之前，使用倒装语序。
例句4：Had it not been for the PLA，we wouldn’t have been able to beat the flood.4要不是人民解放军，我们是无法战胜洪水的。
例句5：Were he here now，he would certainly help me.5他要是在这里肯定会帮我的忙。
注4：例句4中的从句部分出现了否定词not，如果把该句还原成正常语序，应该是：
If it hadn’t been for the PLA，we wouldn’t have been able to beat the flood.
但是一旦句子发生了省略，就必须把hadn’t分开，否定词not还原，放在主语之后，不可写成Hadn’t it been for的形式。
注5：在虚拟条件从句中，动词be在正常语序中常用were，在口语中，当主语是第一、第三人称单数时，可用was，但在if的倒装句中，必须用were。
(三)错综时间条件句
有时，从句和主句中所表示的动作发生的时间是不一致的，这时就要根据其所表示的时间来进行调整。
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。(从句与现在事实相反，主句与过去事实相反)
例句7：If you had gone to see the doctor，you would be all right now.你要早去看病，你现在就没事了。(从句与过去事实相反，主句与现在事实相反)
(四)含蓄条件句
虚拟的条件有时可以不用条件从句来表示，而是通过某些介词短语来表达。
例句8：But for the English test，I would have gone home this week.6要不是英语测试，我这个礼拜就回家了。
注6：除了but for(要不是)以外，能够表示虚拟条件的词和短语还包括：but that(要不是)、without(没有)、otherwise(否则)、or(不然)、under...circumstances(在……的情况下)、in the past(在过去)等等。
过级考试真题
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、虚拟语气在其他从句中的用法
(一)宾语从句
1.wish后的宾语从句
例句9：I wish I were as young as you.7我希望自己像你一样年轻。
注7：wish从句后使用虚拟语气时，动词的形式根据所表示的时间概念而采用不同形式：过去时(与现在相反)、过去完成时(与过去事实相反)或过去将来时(与将来事实相反)。
2.would rather和would sooner后的宾语从句
两个词组都表示宁愿、宁可的意思，后面如用宾语从句，动词采用过去时(与现在或将来事实相反)或过去完成时(与过去事实相反)。
例句10：I’d rather I hadn’t met you.8我宁愿从来就没遇见过你。
注8：would rather和would sooner两词组除了要掌握它们后面宾语从句中虚拟语气的用法以外，还要知道这两个词组后面都可以直接加动词原形，这也是四、六级考试中的一大考点，如：美国歌曲《山鹰》中的第一句歌词就是：I’d rather be asparrow than a snail.其中，就使用了句式would rather do than do(宁愿做……而不做……)。
3.suggest等动词后的宾语从句
表示主观判断、推测、建议、命令和要求的动词通常引起虚拟的宾语从句，此类动词后的宾语从句中采用should +do、should可以省略的虚拟语气形式。该类动词包括：
(1)高中词汇：advise(劝告)、ask(要求)、decide(决定)、insist(坚持)、order(下令)、suggest(建议)等。
(2)四、六级常考词汇：command(命令)、demand(要求)、desire(渴望)、propose(提议)、recommend(劝告)、require(要求)等。
(3)其他词汇：consent(同意)、deserve(值得提
起)、maintain(主张)、move(提议)、urge(极力主张)、 vote(提议)等。
例句11：I recommend that you all be diligent if you want to pass the exam.如果你们要考及格，我劝你们勤奋学习。
(二)主语从句
在It is +形容词/某些动词的过去分词+主语从句的结构中，从句的谓语动词须用动词原形或 should +do的形式。这些形容词包括：
(1)高中词汇：decided(决定的)、important(重要的)、ordered(命令的)等。
(2)四、六级常考词汇：advisable(合理的)、demanded(要求的)、desired(期望的)、desirable(合乎需要的)、essential(紧要的)、insistent(坚持的)、natural(自然的)、preferable(更可取的)、proposed(建议的)、 recommended(推荐的)、required(要求的)、urgent(紧迫的)、vital(极其重要的)等。
(3)其他词汇：appropriate(适当的)、arranged(安排好的)、better(较好的)、imperative(迫切的)、possible(可能的)、probable(可能的)、resolved(决心的)、 strange(奇怪的)、suggested(建议的)等。
例句12：It is highly desirable that a new mayor be appointed for this city.这座城市急需任命一位新市长。
(三)表语从句和同位语从句
有些名词引起的表语从句或同位语从句中，谓语动词须用动词原形或should +do的形式。这些名词包括：advice(忠告)、decision(决定)、demand(要求)、desire(渴望)、idea(想法)、motion(提议)、necessity(必要性)、order(命令)、plan(计划)、preference(偏爱)、proposal(建议)、recommendation(推荐)、requirement(要求)、suggestion(建议)等。
例句13：His proposal is that we turn off TVfor half an hour every day.他建议我们每天少看半个小时的电视。
特别提示：从以上的各类从句中我们可以得到以下的推论，即当一个动词后面的宾语从句中要使用(should)+do的虚拟语气形式时，则可推理出用法相同的一组从句。以动词advise为例：
(1)I advise that we stay and wait here.(动词后的宾语从句)
(2)It is advised that we stay here.(It is +动词的过去分词+that引导的主语从句)
(3)It is advisable that we stay here.(It is +由该动词转换的形容词+that引导的主语从句)
(4)My advice is that we stay here.(由该动词转换的名词后的表语从句)
(5)I offered the advice that we stay here.(由该动词转换的名词后的同位语从句)
(6)I think it advisable that we stay here.(由该动词转换的形容词作宾语补足语，it为形式宾语，真正的宾语从句中使用虚拟语气)
以上六类从句中所使用的都为(should)+do的虚拟语气形式。
历年MBA考题
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)状语从句
1.as if/as though引导的状语从句
as if/as though(仿佛、好像)引起方式状语从句，从句中的虚拟语气形式与wish后的宾语从句相同：
a.一般过去时(表示与现在事实相反)
b.过去完成时(表示与过去事实相反)
c.would +do(表示与将来事实相反)
例句14：You look as if you had seen a ghost.你看起来好像撞见鬼了。
2.lest/in case /for fear that引导的状语从句
lest(以防、以免)、in case(万一、以防)、for fear that(因恐、免得)引起的状语从句中，谓语动词要使用(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等引导的状语从句
由连接代词whoever(无论谁)、whatever(无论什么)、whichever(无论哪个)等和连接副词however(无论如何)、whenever(无论何时)、wherever(无论哪里)等及 no matter+how/what/when /where /who(无论怎样/什么/何时/哪里/谁)构成的词组引导的让步状语从句，若表示说话人对现在或将来的推测，谓语动词常用虚拟语气，形式为动词原形或may /might+do。
例句16：Whichever be the case，my situation remained the same.无论是哪种情况，我的处境都一样。
(五)定语从句
It is time(是……时候了)，Itis about time(差不多是……时候了)，It is high time that(该……了)句式中，that引导的定语从句中用过去时表示虚拟。
例句17：It is time that we protected our environment.我们应该保护我们的环境了。
三、虚拟语气在表示祝愿的句子中的应用
在if only或if...only(但愿、要是……就好了)引起的表示遗憾的感叹句中，谓语动词使用虚拟语气，形式为过去时。
例句18：If only I could see Jordan.我要是能见到乔丹就好了。
以上的十八句是笔者精心设计的，每一个句子都是虚拟语气的一个考点，如果能够把这十八句融会贯通，达到举一反三的程度，虚拟语气部分则可轻松过关。
历年考研试题
25.There is a real possibility that these animals could be frightened， a sudden loud noise.
