虚拟语气
多数中国人对虚拟语气的理解是：虚拟语气表示说话人的愿望，是假设的，虚构的，与事实相反的，或者是不太可能的。这种理解固然是对的，但并不全面。在英语中，虚拟语气是个广义的概念，包括好几种句型和结构。假设，意愿等只是虚拟语气的两个方面。
英汉两种语言表达虚拟语气的方式差异：
而在英语中，虚拟语气是通过句子中谓语动词的特殊形式来表示的。这又一次证明动词在英语中的核心地位，又一次证明要学好英语语法，就要学好英语动词。由于虚拟语气是通过句子中谓语动词的特殊形式来表示的，因此，掌握虚拟语气中所使用的各种谓语动词形式变化是掌握虚拟语气的关键，这也是虚拟语气的难点。虚拟语气本身也是英语语法的一个难点。
学习虚拟语气的方法是分别弄通虚拟语气的各种句型和结构，各个击破。下面对虚拟语气在各种句式中的用法分别介绍。
（一）虚拟语气用于表示假设的条件状语从句，状语从句相当于汉语的“假如…” “要是…”等。
请看一个句子：
If she invites me tomorrow, I shall go to the party. 如果她明天邀请我参加聚会，我就去。
这是个带条件从句的主从复合句，是直接的陈述语气，主句谓语动词用将来时，从句谓语动词用现在时代替将来时，表示能实现的动作。这句话说明说话人认为邀请的可能性较大。此句的条件是“只要她邀请我”，“去”这一动作就能实现。
请把这句话与下面虚拟语气的带条件从句的主从复合句进行比较：
1） If she invited me, I should go to the party. 假如她邀请我参加聚会，我就去。（说话人认为邀请的可能性较小或不可能。）
这句话主句谓语动词用过去将来时，从句谓语动词用一般过去时，其含义是：
She will probably not invite me, so I shall not go to the party. 她很可能不会邀请我参加聚会，所以我不会去。
2） If she had invited me yesterday, I should have gone to the party. 假如她昨天邀请我参加聚会，我就去了。
这句话主句谓语动词用“should ＋ have + 过去分词”形式，从句用过去完成时，对过去发生的事情进行虚拟假设，表示与过去事实相反的情况，其含义是：
She didn’t invite me yesterday, so I didn’t go to the party. 她昨天没有邀请我参加聚会，因此我没有去。
3） If she should invite me tomorrow, I should go to the party. 如果她明天邀请我参加聚会，我会去的。
这句话主句谓语动词用过去将来时，从句谓语动词也用过去将来时，表示的意思是，“邀请我”的可能性较小，对将来要发生的情况表示怀疑。其含义是：
It is unlikely that she will invite me tomorrow, so I shall not go to the party. 明天她不可能会邀请我，因此我不会去。
从以上例句可以看出：虚拟语气的条件句是用谓语动词的特殊形式来表示与现在、过去事实相反的情况或对将来发生的情况表示怀疑，和直陈语气条件句的谓语动词形式以及所表达的含义完全不同。虚拟语气条件句中所用的谓语动词过去式、过去完成式、过去将来式等只表示不同的虚拟语气，与直陈语气句子的过去时、过去完成时等毫无关系，在学习时应注意加以区别，不要混淆。
现将虚拟语气在条件句中的各种具体形式和用法分述如下：
1、对现在的虚拟，表示与现在事实相反的假设时，条件状语从句的谓语动词用过去式（be的过去式用were.而主句中的谓语动词用would (should, could, might) + 动词原形。见下表：
1、例句：
If I were you, I should study English.
(fact: I am not you, so I shall not study English.)
If he had time, he would attend the meeting.
(fact: He does not have time, so he will not attend the meeting.)
If they didn’t take physical exercises every day, they wouldn’t be so healthy.
(fact: They take physical exercises every day, so they are very healthy.)
If you went to bed earlier, you would not be so sleepy in the morning.
(fact: You often go to bed late, so you are always sleepy in the morning.)
If this were the case, it would be very awkward.
(fact: This is not the case, so it is not awkward.)
Now let’s do some translation:
要是没有虚拟语气，英语就会容易多了。
If there were no subjunctive mood, English would be much easier.
如果我是你，我就在房屋周围种些树。
If I were you, I would (should) plant some trees around the house.
如果我把头发染成蓝色，人人都会笑话我。
If I dyed my hair blue, everybody would laugh at me. Or: I would (should) be laughed at by everybody.
要不是她这么忙，她就会出席今天下午的会议了。
If she were not so busy, she would attend the meeting this afternoon.
2、对过去的虚拟，表示与过去的事实相反的假设时，条件状语从句的谓语动词用过去完成时,主句的谓语动词用would (should, could, might)+过去分词。见下表：
例句：
If you had taken my advice, you wouldn’t have failed in the examination.
(fact: You did not take my advice, so you have failed in the examination.)
I would have checked my paper again if I had had more time at yesterday’s examination.
(fact: I did not have more time at yesterday’s exam, so I didn’t check my paper again.)
He would have already recovered from his illness if he had seen the doctor in time. (fact: He didn’t see the doctor in time, so he has not recovered from his illness.)
If we had known that she was to arrive yesterday, we could have met her at the station.
(fact: We didn’t know that she was to arrive yesterday, so we could not meet her at the station.)
You didn’t let me drive. If we had driven in turn, you wouldn’t have got so tired.
(fact: We didn’t drive in turn, so you have got so tired.)
Now let’s do some translation:
要是有人警告过他，他就不会吃那个食物了。
If he had been warned, he would not have taken that food.
如果你服从命令的话，灾难就不会发生了。
If you had obeyed the order, the disaster could not have happened.
假如你早接受了那个有经验的老工人的意见，你的试验就不会失败了。
If you had taken the old experienced worker’s advice, you wouldn’t have failed in the experiment.
如果我知道你要来的话，我就去机场接你了。
If I had known that you were to arrive, I would have met you at the airport.
如果我的律师上周六在这里，他就会阻止我去了。
If my lawyer had been here last Saturday, he would have prevented me from going.
要是她工作更努力些，她本是成功的。
If she had worked harder, she would have succeeded.
会上我没有见到你妹妹。如果她来了，她就见到我哥哥了。
I didn’t see your younger sister at the meeting. If she had come, she would have met my elder brother.
3、表示与将来事实相反的假设，对将来表示怀疑，或将来的动作不太可能实现时，条件状语从句和主句的谓语动词有以下形式：（见表）
请看以下句子：
1）If it rains tomorrow, our picnic will be put off. (说明：The weather has been very changeable these days.) 条件状语从句的谓语动词用现在时，表示说话人认为下雨的可能性很大。
2）If it rained tomorrow, our picnic would be put off. (说明：The weather has been very good these days.) 条件状语从句的谓语动词用过去时，表示说话人认为下雨的可能性不大。
3）If it should rain tomorrow, our picnic would be put off. (万一明天下雨，我们的野餐就推迟)。条件状语从句的谓语动词用should＋动词原形，说明下雨的可能性很小或没有可能，如果下雨，那将是出乎意料的。
4）If it were to rain tomorrow, our picnic would be put off.这句话与上一句意思几乎一模一样。
If I saw him tomorrow, I would pass your note to him.
If she were to miss the train tomorrow, she might come back and start off again the day after tomorrow.
万一你失败了，你准备怎么办？
If you should fail, what would you do?
要是我明天真的见到她，我就把真相告诉她。
If I were to see her tomorrow, I would tell her the truth.
万一明天下雨，会议就推迟。
If it were to rain tomorrow, the meeting would be put off.
我打赌巴西会赢得世界杯。要是巴西输了，我就请你搓一顿。
I bet Brazil will win the World Cup. If it should lose, I would treat you a meal.
4、当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，动词的形式要根据它所表示的时间来调整。这与以上三种情况不同，虚拟语气的谓语动词形式没有遵循以上规律。
For example:
If you had worked hard, you would be very tired. (从句说的是过去，主句指的是现在。)
If he had followed the doctor’s advice, he would be quite all right now.
If I were you, I would have gone home.
Now let’s do some translation:
如果她过去没有刻苦训练的话，就不会跑得这么快。（从句动作指的是过去，主句指的是现在的情况）(Fact: She has trained very hard, so she is able to run very fast now.)
If she hadn’t trained so hard, she wouldn’t be able to run so fast.
如果你当初每天都练习说英语的话，你的英语就会说得很好。（从句动作指的是过去，主句指的是现在的情况） （fact: You didn’t practice speaking English very hard every day, so you can’t speak English very well ）
If you had practiced speaking English every day, you would speak English well enough.
5. 以上句型可以转换成以下形式：
1）条件状语从句省略if：在书面语中，如果条件状语从句的谓语中有were, had 或should, 就可以省略if, 并将were, had 或should 放到句首，谓语主语之前，用 “Were/Had/Should + 主语”的形式。这种虚拟语气在意义上与带if 的条件状语从句相同。当然，如果从句没有were, had, 或should,就不能省略if.
Now let’s look at some examples:
If I were to do it, I’d do it some other way. →Were I to do it, I’d do it some other way.
If you should fail, try again. →Should you fail, try again.
If you had been here earlier, you would have seen him. →Had you been here earlier, you would have seen him.
但是，If you came tomorrow, we would have the meeting.这句话if 就不能省略。
而且，在虚拟条件状语从句中，省略了if的倒装形式的句首不能用动词的缩略形式。如我们可以说：
Were it not for the expense, I would go to Italy.
但不能说：Weren’t it for the expense, I would go to Italy.
Please do not use “if”：
如果我是你，我每天早上就早起床。
Were I you, I would get up early every morning.
假如你昨天早十分钟到达火车站，你就赶上火车了。
Had you arrived at the station ten minutes earlier yesterday, you could have caught the train.
要是明天有会议，我就会来。
Should there be a meeting, I would come.
2）用介词短语代替条件状语从句。（可以改为条件状语从句）。例如：
Without air, there would be no living things.
But for your help, I couldn’t have done it.
Without electricity human life would be quite different today.
Now let’s do some translation. 请用介词短语代替条件状语从句。
要不是你的帮助，我就失败了。
But for (except, without) your help, I would have failed.
如果没有恰当的控制手段，核反应堆就会爆炸。
Without proper means of control, a nuclear reactor would explode.
3）用其他方式代替条件状语从句（可以改写为条件状语从句。）例如：
It would produce bad results to do that. 用动词不定式 =If you did that/should do that, it would produce bad results.
She would have come, but she wasn’t informed, nor invited. （用but.）=She would have come, if she had been informed or invited.
A more responsible person would not have left the work half done. 一个更负责的人是不会把工作做到一半就不管的。(用比较级) ＝If you (he, she) were more responsible, you (he, she) would not have left the work half done.
Now let’s do some translation:
聪明一点的人是不会干出这等蠢事的。
A wiser man would not have done such a foolish thing.
我应该早点写完这封信，但我一直很忙。
I should have written the letter earlier. But I have been very busy.
要能登上珠穆朗玛峰，那经历该多棒！
It would be a fantastic experience to climb up to Mount Everest.
6、虚拟语气省略条件从句或主句
表示虚拟语气的条件句的主句或从句有时可以省略，而省略部分的含义仍有所体现。
1）省略条件从句，如：
It would be very nice.
You could have done it yourself. (省略If you had wanted to.上下文可以看出You didn’t want to.) (Fact: You didn’t do the work yourself because you didn’t want to.)
I wouldn’t smoke. (省略If I were you.) (表面上说我，实际上说你。这是一种委婉的表达法。（Fact: You smoke very often. I advise you not to smoke any more.）
2）省略主句：在强调条件从句时，常省略主句，这种句子常表示一种“已不能实现”的愿望，主要用于If only 引导的感叹句中。
For example:
If only he were here!
If only I knew more!
If only he had stayed with us!
Now let’s do some translation:
要是我听了他的建议就好了！
If only I had taken his advice!
我如果是一只鸟就好了！
If only I were a bird.
快用If only 造三个句子，表达你的愿望！
If only I could live in a big apartment!
If only I were a billionaire!
If only I could marry her/him!
（二）虚拟语气的其他句型和用法
1、用在“wish+宾语从句”中，表示很难实现或不能实现的愿望，可以翻译为“但愿…”, “悔不该…”等。表示现在不能实现的愿望，从句的谓语动词用过去式；表示将来的愿望，从句的谓语动词用“would (could)+动词原形”；对过去的事情表示愿望，从句的谓语动词用 “had+过去分词” 或“could + have + 过去分词”。Wish 后面的宾语从句必须用虚拟语气，不管这个愿望是否能实现。如：
I wish it were Spring all the year round.
I wish you could go with us.
We wish we had arrived there two hours earlier.
Now let’s do some translation using “wish”:
我要是Jane 就好了。
I wish I were Jane.
他真希望自己生活在中世纪。
He really wishes that he were living in the Middle Ages.
但愿北京整年是秋天。
I wish it were autumn in Beijing all the year round.
要是你能同我们一起过寒假就好了。
We wish you would spend the winter vacation with us.
我要是没有买这辆车就好了。
I wish I had not bought this car.
Now, it’s time for you to make three wishes about your present, future, and past..
I wish I were twenty years younger.
I wish I could work for an NGO.
I wish I had studied law in college.
注意：wish 与hope接宾语从句的区别在于：hope表示一般可以实现的希望，宾语从句用陈述语气。Wish表示很难或不大可能实现的愿望，宾语从句用虚拟语气。请比较：
We hope we will succeed. (We don’t know if we will succeed.)
We wish we would succeed. (We know we can hardly succeed.)
2、用在as if/as though,或even if/even though引导的从句中: 这时，如果从句中表示的动作发生在过去，则谓语动词用had＋过去分词形式；如果指的时现在的状况，则用过去式(be用were)；指将来则用would(should, could)+动词原形。这里只看从句动作发生的时间，与主句的时态没有关系。
For example:
Some metals look at first sight as though they were gold.
He looked as if he were an artist.
He speaks English so fluently as if he had studied English in the U.S.
He always sounds as if he would help you.
When a pencil is partly in a glass of water, it looks as if it were broken.
Even if he were here, he could not solve the problem.
看她的样子，好像生病了。
She looks as if/though she were ill.
他走起路来就好像他是国王。
He walks as if he were a king.
他表现得若无其事。
He acted as if nothing had happened.
即使天塌下来，他也不会辞职。
He would not resign even if the heaven should collapse.
3、在It is (high) time (that)…句型中，后面的从句的谓语动词常用过去式(be的过去式用were), 或用should+动词原形(should 不能省略)来表示。这句话的意思是“（现在）该…”。For example:
It is time we left/should leave.
It is high time that you got married.
It is time that I bought a car.
Now it is time that you made some sentences by using this pattern. Think about what you should do now.
该你用这个句型造几个句子了。
It is high time that I should lose some weight.
It is time that I bought an apartment.
It is time that we took a rest.
4、在 I would rather (that)…句型中，后面的从句的谓语动词用过去式(be的过去式用were)。这句话的意思是“我宁可…”，表示说话人的意愿。
For example:
I’d rather I were in the rain now.
I’d rather you did not tell him.
5、用在suppose开头的祈使句中，从句的谓语动词变化与as if后面的动词变化规律相同，用过去式、过去完成式、或过去将来式。意思是“假如…”，但suppose 是动词，不是连词。如：
Suppose the boss walked in. What should I do?
Suppose Saddam had not been captured. What would the U.S. do?
Suppose Chen Shui-bian should declare Taiwan independent. What would China do?
6、用在for fear that或lest引导的从句中，表示“怕…”“万一…”等意思。从句的谓语动词用should＋动词原形，should 可以省略。如：
She closed the windows for fear that she (should) catch cold.
The officer forbade the use of artillery lest the city’s industry be damaged.
Lest the wall should collapse, they evacuated from the building.
7. 在表示建议、要求、命令等意思的动词，如arrange, command, demand, desire, insist, order, propose, request, require, suggest, beg, move（提议）后面的宾语从句中，谓语动词用should + 动词原形，should 可以省略，而引导宾语从句的that 不能省略。例如：
We suggested that we (should) have a meeting.
We insisted that they (should) go with us.
The doctor ordered that she (should) stay in bed for a few days.
He demanded that we (should) start right away.
The commander ordered that the bridge (should) be bombed.
The villagers requested that the old building not be pulled down.
Now let’s do some translation:
总经理坚持该项目必须按计划执行。
The general manager insisted that the project be carried out as planned.
省长请求再给他一次机会。
The governor requested that he be given another chance.
美国要求伊朗必须无条件放弃其核武器计划。
The United States demanded that Iran should unconditionally give up its nuclear weapon program (program to develop nuclear weapons)
最高法院裁定此案必须重新审理。
The Supreme Court ruled that this case be retried.
医生建议，即使在节假日人们也不应该熬夜。
Doctors suggest that people should not stay up late even on holidays.
注意：suggest 表示“暗示”时，宾语从句不用虚拟语气。Insist后面强调的是事实时，宾语从句也不用虚拟语气。如：
The neighbor suggested that his wife was having an affair.
He insisted that he was right.
Mike insisted that he had never stolen anything.
8、使用上述表示建议、要求、命令等意思的动词派生的名词，或在这些动词用作名词时，名词之后的从句用虚拟语气，即从句的谓语动词用should＋动词原形，should 可以省略。从句的引导词that 不能省略。这与上述第7项类似。如：
He made a request that he (should) be allowed to take 3 days off. = He requested that he be allowed to take 3 days off.
Our suggestion is that education not be industrialized. = We suggest that education not be industrialized.
The president’s decision is that the war against terrorism be launched at the right time. =The president decided that the war against terrorism be launched at the right time.
9、上述动词在It is suggested that…, It is required that…, It’s requested that…, It’s ordered that…, It’s arranged that…句型中，that 之后的从句用虚拟语气，即谓语动词用should+动词原形, should 可以省略，但引导词that 不能省略。如：
It was suggested that he attend the conference.
It was requested that the trial be openly reported.
10、在It’s important (imperative, necessary, essential, vital, desirable, advisable, better) that…句型中，that 引导的从句用虚拟语气，即谓语动词用should ＋ 动词原形,should可以省略。这个句型表示说话人的意见、要求等。
For example:
It is essential that there should be enough food and clothing for the winter.
It is desirable that your wedding be postponed until next July.
It is imperative that the board chairman be present at the board meeting.
另外，在一些习惯用语中也有虚拟语气的形式。但最好把这些习惯用语作为一种句型来记住。如：
May you be happy!
May you succeed!
Long live the People’s Republic of China!
Everybody leave the room!
You had better not resign.
I would rather not tell you.
总之，虚拟语气是英语中的一个难点，因为虚拟语气的用法和句型较多，动词的变化比较复杂。在学习的时候要逐个过关。同时，也要善于发现虚拟语气的规律。根据动词的变化，大致可以把虚拟语气分为三种：
一种是动词用过去式，过去分词式，或过去将来式，这主要是用if…, wish, suppose的情况；
一种是动词用should+动词原形（should可以省略），这主要用于表示建议、要求、命令等意思的动词或名词后面所接的从句，以及It is important (necessary) that…后面所接的从句；
一种是动词用过去式，如It is (high) time (that)…和I would rather 后面的从句。同学们还可以自己总结适合自己的规律，如把虚拟语气句型可以分为用于简单句、条件状语从句、宾语从句、主语从句、表语从句、定语从句、同位语从句等。
Now let’s do some exercises to consolidate what we have learned about subjunctive mood:
一、单项选择：
1. The teacher demanded that the exam ___before eleven.
a. must finish b. would be finished c. be finished d. must be finished
2. She made the demand that she ____ at once.
a. leave b. leaves c. left d. to be left
3. He is talking so much about America as if he ____ there.
a. had been b. has been c. was d. been
4. Mother insisted that the child’s hands ___ before dinner.
a. should wash b. be washed c. would wash d. had washed
5. 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 set
6. Mother suggested that I ___ my homework first before watching TV.
a. did b. do c. shall do d. have done
7. My suggestion was that the meeting ____ off till next week.
a. to put b. be put c. should put d. be putting
8. The suggestion has been made ___the basketball game ___ put off.
a. for; to b. that; be c. which; should be d. to; being
9. The commander ordered that the wounded ___ to hospital right away.
a. to be sent b. be sent c. send d. should send
10. The order came that the medical suppliers ____ to the village without delay.
a. would be sent b. should send c. be sent d. must be sent
11. They requested that he ____ on the radio
a. spoke b. speaks c. speak d. would speak
12. It is important that we ___ wild animals.
a. will protect b. should protect c. shall protect d. are protecting
13. It is necessary that the problem ____ at once.
a. solves b. should solve c. should be solved d. will be solved
14. It is strange that he ____ interest in much of his research.
a. should have lost b. would lose c. had lost d. will lose
15. Had you listened to the doctor, you ___ all right now.
a. are b. were c. would be d. would have been
16. ___ I be free tomorrow, I could go with you.
a. Could b. Should c. Might d. Must
17. ___ to do the work, I should do it some other way.
a. If were I B. I were c. Were I d. Was I
18. ___ today, he would get there by Friday.
a. Would he leave b. Was he leaving c. Were he to leave d. If he leave
19. ____ your letter, I would have written back two days ago.
a. If I received b. Should I receive c. Had I received d. If I could have received
20. ____, he would have passed the exam.
a. If he were to study b. If he studied hard
c. Had he studied hard d. Should he study hard
21. Should it rain, the crops ___.
a. would be saved b. would have been saved c. will be saved d. had been saved
22. You ___ earlier. The bus left a moment ago.
a. would come b. should have come c. may come d. have come
23. He treated me as though ___ his own son.
a. I am b. I would be c. I was d. I were
24. He smiled as if he ____ my thought.
a. read b. was reading c. had read d. has read
25. I ____ you some money, but I hadn’t any on me then.
a. would lend b. would have lent c. could lend d. may have lent
26. He talks as if he ____.
a. knows all about it b. has known all about it c. knew all about it d. knowing all about it
27. “Have you ever been to Beijing?” “No, but I wish I ___.”
a. have b. will c. do d. had
28. Where is Xiao Zhang? I wish I ____ him at once.
a. can find b. will find c. could find d. could have found
29. I wish I ___ there then.
a. was b. were c. had been d. would be
30. It is time we ___ to bed.
a. must go b. will go c. went d. have gone
31. If I ____ you, I would try again.
a. am b. was c. were d. be
32. _____, all the students would hear.
a. If the teacher had spoken louder b. If the teacher will speak louder
c. Had the teacher spoken louder d. If the teacher spoke louder
33. What should we do if it ____ tomorrow?
a. should snow b. would snow c. snow d. will snow
34. If you _____ 5 minutes earlier, you _____ him.
a. should come; had seen b. came; would see
c. come; will see ?d. had come; would have seen
35. If only I ____ my watch.
a. hadn’t lost b. haven’t lost c. didn’t lose d. don’t lose
36. You _____ such a serious mistake if you had followed his advice.
a. may not make b. might have not made
c. shouldn’t have made d. might not have made
37. He ____ the test, but he wasn’t careful enough.
a. could have passed b. were able to pass c. must have passed d. might be able to pass
38. We ____ the work on time without your help.
a. hadn’t finished b. didn’t have finished c. couldn’t have finished d. can’t have finished
39. If you ____ at school, you _____ a college student now.
a. had studied hard; would have been b. should have studied hard; should have been
c. had studied hard; would be d. would study hard; must have been
40. If only I ____ as young as you are!
a. being b. am c. be d. were
二、改错
1. I wish that it is true.
答案：is 改为were
2. The doctor suggests that she will not smoke.
答案：will 改为should, 或去掉will
3. She insists that they must give her a receipt.
答案：must 改为should, 或去掉must
4. Bill wished that he is more interested in his work.
答案：is改为were
5. He would be a good sportsman now if he trained regularly.
答案：trained 前面加上had
6. I wish that somebody teaches me to sew.
答案：teaches 改为taught
7. I wish that you saw the charming opera yesterday.
答案：saw 改为had seen
8. This is not my dictionary. If it is mine I will lend it to you.
答案：第二句话改为If it were mine I would lend it to you.
9. If my watch were not slow yesterday, I would not have been late.
答案：were not 改为 had not been
10. If she had worked hard enough, she would pass the English exam.
答案：would pass 改为would have passed
11. If we could finish our work a little earlier today, we shall go to see the film.
答案：shall 改为should
12. What would be happened, if there were no sun, air or water?
答案：be happened 改为happen
13. Should the weather fine, we might go on a trip.
答案：fine 前面加上be
14. If it were not rain tomorrow, they might went to the Great Wall.
答案：rain 前面加上to, went 改为go
15. Long lives our motherland!
答案：lives 改为live