爱华网虚拟语气
虚拟语气（The SubjunctiveMood）是用来表示与客观事实相反或可能相反的愿望、假设、怀疑、想象、建议、推测等的一种谓语动词形式。虚拟语气主要用于条件从句、宾语从句、主语从句、同位语从句、状语从句以及其它一些表示祝愿或使语气更加委婉的结构中，其具体用法如下。
1．与现在事实相反的虚拟语气
条件从句的谓语动词形式用过去式（be的过去式多用were），而主句的谓语动词形式用would/should/could/might加动词原形（would用于第二、第三人称，should用于第一人称，但在美国英语中,第一人称也可用would。以下同此）。
If there were no gravity, we should not beable to walk.
如果没有引力，我们也就不能走动。
If it were not for friction, our housesw ould fall apart.
如果没有了摩擦力，我们的房屋就会坍塌。
Even if he had enough money, he wouldn’tbuy it.
即使有足够的钱，他也不会买的。
2．与过去事实相反的虚拟语气
条件从句的谓语动词用had加过去分词，主句的谓语动词用would/should/could/might加have再加过去分词形式。
If I had known about that, I would havemet you at the airport.
如果我早知道的话，我会去机场接你的。
If it had not been for your help, wewould’t have achieved so much.
如果不是你的帮助，我们不会取得如此大的成就。
3．与将来事实相反的虚拟语气
条件从句的谓语动词用过去式(be的过去式用were)或should加动词原形或were to 加动词原形，主句的谓语动词则用would/should/could/might加动词原形。
If you dropped the glass, it would breakinto pieces.
如果你把杯子掉到地上，它就会摔碎的。
If it should snow tomorrow, I would’t getup early.
如果明天下雪的话，我就不早起了。
If I were to do the experiment, I shouldread the instruction in every detail and particular.
如果由我做这个实验的话，我会详详细细地阅读说明书的。
4．由wish引导的虚拟语气
wish后宾语从句的谓语动词可以用过去式（be的过去式用were，适合于各个人称，当然，单数第一、三人称时也可以用was），表示当时未能实现的愿望；也可以用过去完成式，表示过去未能实现的愿望；还可以用would/could/might加动词原形，表示将来不大可能实现的愿望。
I wish I were as young as you.我多么希望能像你一样年轻。
We wish we could live on the moon in thefuture. 我们希望将来能生活于月球上。
I wish I had paid more attention to mystudy of English when I was in middle school.
我真希望在中学时能够好好学习英语。
The boy wishes he were being with ustomorrow morning.
那个男孩儿希望明天上午能与我们在一起。
注：动词wish如果是过去式，其后宾语从句的虚拟语气形式仍根据实际情况使用相应的过去式、过去完成式等。
The girl wished she knew how todrive. 那女孩子真希望她会开车。
I wished you all would get richer andricher. 我希望你们会越来越有钱。
Elizabeth wished that she hadn’t beenmarried. 伊丽莎白真希望她没有结婚。
5. 由wouldrather等引导的虚拟语气
在表示“宁愿，希望”之意的词组如 wouldrather, would sooner, would prefer, would just assoon等引导的从句中（从句中的that常省略），谓语动词用过去式表示现在或将来难以实现的愿望；用过去完成式表示过去未能实现的愿望。
I would rather you gave me a definiteanswer now.
我希望你现在能给我一个明确答案。
I would just as soon you had returned thebook yesterday.
我多么希望你昨天能把书还给我。
6．as if或as though引导的虚拟语气
在asif或as though引导的方式状语从句中，谓语动词用过去式（be用were）表示与现在事实相反的假设；用过去完成式表示与过去事实相反的假设；用情态动词加动词原形表示对未来事实的一种假设。
The young man works with such enthusiasmas if he never knew fatigue.
那个年轻人全身心地投入工作，好象他从来就不知道疲倦。
The boy described the town as if hehimself had ever seen it
小男孩描述着那个小镇，好象他自己真的去过似的。
The lady held the pet dog tightly as ifshe would never let it go again.
妇人紧紧搂着她的宠物狗，好象再也不让它离开似的。
7. 由though等引导的虚拟语气
在正式文体中，由if, though,although, whether, whatever, however, no matter…, as/so long as, on conditionthat等引导的条件状语从句或让步状语从句 表示假定、推测时，从句的谓语动词应用动词原形，而主句形式不变。
All matter, whether it be gas, liquid orsolid, is made up of atoms.
所有物质，不论是气体、液体还是固体，都是由原子组成的。
If the rumor be true, everything ispossible.
如果这是事实的话，那么什么事都可能发生的。
However hard it rain, we shall go hometonight.
不管雨下多大，我们今晚都得回家。
So long as a volume hold together, I amnot much troubled as to its outer appearance.
只要书没散开，对于其外观我并不在乎。
8. 由lest等引导的虚拟语气
在由lest, in case, forfear that等引导的表示“以免、恐怕”等意义的目的状语从句中，其从句常用should加动词原形或直接用动词原形（后为美国用法）, 而主句用陈述语气
We were all afraid lest he should be lateagain. 我们都很担心，惟恐他再次迟到。
Here is some money in case you useit.拿着点钱，万一急需什么的。
注：in case引导的从句可以用陈述语气，for fearthat 引导的从句谓语动词也可以用情态动词may/might/would.加动词原形形式。
He bought several bottles of beer in casehis friends visited.
他买了几瓶啤酒以备朋友来访。
Shut the window for fear that it mayrain.
关上窗户，万一下雨呢。
9．由so that等引导的虚拟语气
在sothat及in order that引导的目的状语从句中，从句谓语动词常常用might/should/could加动词原形或直接用动词原形来表达虚拟语气。
The mother averted her face so that herchild shouldn’t see her.
那个母亲扭过脸去，以便不让她的孩子发现她。
She listened carefully in order that shemight discover exactly what the blind man wanted.
她仔细地听，以便能够真正弄明白那个盲人想要的东西。
In order that a body be in equilibriumunder the action of any number of forces,two conditions areneeded. 物体在众多力的作用下要保持平衡得需要两个条件。
10．If only引导的虚拟语气
if only 引导的简单句谓语动词要用虚拟语气形式，其用法与wish的用法相同，但感情色彩更浓。
If only he knew how we misshim.
如果他知道我们有多想念他，那该多好啊。
If only the rescue car had arrived intime.
救援车及时到达就好了。
If only the rain would notstop!
如果雨不停有多好啊！
注：在 ifonly句中，only可以后移，此时可以理解为if非真实条件句的加强语气。
If I had only met you halfway, we wouldn’thave missed each other.
如果我半路碰上你的话，我们也就不会彼此错过了。
11．It is (high) time…句中的虚拟语气
在It is (high/about/good)time…定语从句中，从句的谓语动词多用过去时以表达虚拟语气，个别时候也可以用should/had better/had rather加动词原形。
It is time I were off. 我早该走了。
It is (high) time that the environmentshould be paid more attention to by mankind.
人们早就该对环境加以密切关注了。
注：A. It istime后可以跟to do不定式，表明“到了……时间了”，而后跟虚拟语气从句则表示“早该……”，有“为时稍晚”之意，特别是当time之前有high等修饰时，此意义更为强烈。
It is time to have lunch now. 到了吃午饭的时间了。
You worked so hard this morning. It isgood time you took a nap.
一上午你都在劳累着，该稍微休息一下了。
在It is thefirst/second/third…time that结构中，从句谓语不用虚拟语气形式,而用陈述句的现在完成式。
It is the third time that Tom has beenlate. 这是汤姆第三次迟到了。
12．虚拟语气用于主语从句中
在Itis/was加表示“要求、建议、命令”等的形容词或过去分词再加that从句引导的主语从句中，主语从句的谓语动词一般用should加动词原形（英国用法）或直接用动词原形（美国用法）。此类词有advisable, appropriate, better, compulsory,crucial, desirable, essential, good, imperial, imperative,important, insistent, keen, natural , necessary , possible ,preferable , proper , recommendable , strange, urgent,vital及arranged, decided, demanded, desired, ordered,proposed, recommended, required, resolved, suggested,urged等等．
It is important that every member shouldinform himself of the rules.
重要的是每个成员都要了解这些规则。
It was arranged that they leave thefollowing week.
据安排他们将下周离开。
It was requested that all the students bepresent at the meeting tomorrow.
要求每个学生都得出席明天的会议。
It is imperative that you should arrivehere in time.
你明天必须按时到这儿。
13．虚拟语气用于宾语从句中
在由表示“请求、建议、命令、坚持”等的宾语从句中，其谓语动词应用should加动词原形或直接用动词原形。这类动词包括ask, advise, argue, beg, demand, desire,determine, decide, deserve, insist, intend, maintain, move,propose, order, recommend, require, resolve, request, suggest,urge等。
The employer ordered that the lettershould be delivered at once.
老板要求这封信要立即送出。
We insisted that Mr.Brown chair themeeting.
我们坚持由布朗先生主持会议。
John’s father demands that he stay inBeijing one more day.
约翰的父亲坚持让他再在北京多呆一天。
As soon as the war ended, Einstein urgedthat atomic energy be put to peaceful uses.
战争一结束，爱因斯坦就强烈要求将原子能用于和平目的。
14．虚拟语气用于同位语从句和表语从句中
在表示“命令、建议、计划”等名词后的表语从句和同位语从句中，其谓语动词为should加动词原形，should也可以省略。此类名词有advice, desire, decision, demand, idea,insistence, necessity, plan, resolution, instruction, importance,preference, requirement, recommendation, proposal, suggestion,order, motion, resolution, wish, a pity, a shame, nowonder等等。
I am in favor of the proposal that aspecial committee be set up to examine the case.
我同意成立专门委员会调查此案的建议。
It is a pity that he should turn out to bea liar.
遗憾的是他竟然是个骗子。
The suggestion that students spend a fewyears in English-speaking countries is not practicable. 学生在英语国家呆几年的想法并不现实。
The order that we should retreatimmediately is not from the headquarters.
我们立即撤退的命令并非来自司令部。
15．情态动词加have再加过去分词结构表示的虚拟语气
在这一结构中，would/should/could/might加have再加过去分词表示过去本来可以、能够、应该或必须完成的行为而实际并未完成或表示对过去发生事情的推测。
I would have written that paper daysago.
我本可以在几天前就写完论文的。
You should have prepared well for thistrip.
你本应该为这次旅行做好准备。
The investigation showed that 40 percent of thepeople killed in the accident could have been saved.调查表明事故中百分之四十的死难者本可以获救。
They might have come to a wrongconclusion. 他们或许曾得出错误的结论。
16. 虚拟语气用于表示祝愿的句子中
在表示祝愿、诅咒等的句子中，谓语动词往往采用动词原形以表达虚拟语气。
May you succeed! 祝你成功！
God bless you!上帝保佑你！
Money be hanged!该死的金钱！
Long live our socialistmotherland! 我们的社会主义祖国万岁！
So be it! /Be it so! 但愿如此！
