英语语法—虚拟语气(最全)
虚拟语气
1.虚拟语气的概念
虚拟语气把动作当作一种只存在于讲话人想象中的“假设”或“推测”，而不是当作客观现实中的真实事件。它表达的是建议、不满、怀疑、忧虑、推测、假设、想象、祝愿等。
2.虚拟语气用于非真实条件句
英语中的条件句有两种：真实条件句和非真实条件句。真实条件句实现的可能性非常大，常用if, unless, as long as, so long as, once等引导，谓语动词常用陈述语气；非真实条件句常表示不能实现或纯假象的情况，谓语动词要用虚拟语气。
非真实条件句包括虚拟条件句、推测条件句、错综时间条件句。
①虚拟条件句、推测条件句
虚拟条件句可分为两类：一类是叙述与现在事实相反的情况，一类是叙述与过去事实相反的情况。另外，还有一类用于推测将来的情况，也称作推测条件句。
从句中提出一种与客观现实不相符或根本不可能存在的条件，主句会产生一种不可能获得的结果。句中的虚拟语气根据不同的时间有3种不同的形式：
I would lend him the money if he asked me.
他要是问我，我愿意借钱给他。(意愿)
If he had time, he should do it.
要是有时间，他愿意做那件事。(意愿)
He could move the big stone if he should try.
努力的话，他能搬动那块大石头。(能力)
If he forgot to come, you could go instead.
他要是忘了没来，你可要替他来。(许诺)
A.与现在事实相反
If I had enough money, I would buy a computer.
如果我有足够的钱，我将买一台电脑。(实际上没有) Were I you I would refuse.
如果我是你我会拒绝。(我不是你)
注：从句有时可用If it were not for这种句型，表示“若不是……”。
It it weren’t for your help, we would be in serious trouble.
若不是你帮忙，我们会遇到大麻烦。
You wouldn’t be anywhere if it weren’t for me.
要不是我你不会有任何成就。
B.与过去事实相反
If I had known that you were coming, I would have met you at the airport.
如果我知道你要来，我就会去机场接你了。(实际上不知道)
What would you have done if you’d been in my position.
如果你处于我的位置你会怎么办？
Had I not seen it with my own eyes, I would not have believed it.
这事要不是我亲眼所见，我都不会相信的。
注：从句有时也可用If it had not been for这种句型，表示“要不是……”。
If it hadn’t been for your timely help, we would have got into serious trouble.
要不是你及时帮组，我们会陷入严重的困境。
Had it not been for their support, we couldn’t have won the election.
要不是有他们的支持，我们不可能赢得选举。
C.与将来事实相反
If you succeeded, everything would be all right.
如果你将来成功了，一切都会好的。
If I were to do the job, I would do it in a different way.
要是我来做这工作，我会是另一种做法。
If it should rain tomorrow, what else could we do?
要是明天下雨的话，我们还能做什么呢？
D.虚拟条件句、推测条件句用法注意事项
I. 虚拟语气不可用if表示条件，而用介词without, but for等或连词
otherwise等表示一种含蓄条件。
Thank you for all your hard work. I don’t think we could have managed it without you.
谢谢你的努力工作。要是没有你，我们完不成任务。
II．如果省略的条件句中的谓语动词是否定形式，要用Were it not for…/Had it not been for…, 不能把缩略形式的weren’t/hadn’t放在it之前，not只能在it之后，were也不能用was代替。
III. 有时，在虚拟条件句中，主、从句可以省略其中的一个，来表示说话人的一种强烈的感情。
If I were a millionaire.
要是我是个百万富翁就号了。(省略主句)
You could have arrived in time.
你应该能准时到达的。(省略从句)
IV. 虚拟条件句中的谓语可用进行时，表示“如果……正在……”等，主句的谓语仍用would/should/could/might，并可根据情况选用时态。
If human beings were not killing each other, we could be living a happy life.
要是人类不自相残杀的话，我们就会过上幸福的生活。
If you hadn’t been studying so hard, you might have failed the exam.
要不是你一直刻苦学习的话，你就可能通不过考试。
V. 当虚拟条件句中的谓语动词含有were, should, had时，if可以省略，而
将were, should, had置于主语前，用倒装结构。
Had you informed me earlier, I would have signed the contract.
要是你早些告诉我的话，我就会签了那份合同。
VI. 虚拟语气中的主句通常是陈述句，但也可以是疑问句/感叹句/祈使句。If she had everything, would she be happy?
如果她什么都有，她会幸福吗？
If he had married her, how happy he would have been!
他要是娶了她的话，他该是多么幸福啊！
If you were man enough, don’t give up.
如果你是个男子汉的话，就不要放弃。
VII. could have + 过去分词也可用于虚拟条件句中，此时的could是情态动词，表示“能够”，相当于had been able to…。
If I could have earned enough money, I should have travelled over the world. 要是我挣的钱足够多的话，我就能周游世界了。
If you could have prevented mistakes, you might have been more successful. 如果你能避免错误的话，你会更加成功的。
VIII. 在同一个句子中，不能一部分表示真实条件，另一部分表示非真实条件，不然会破坏句子的一致性。
If I had the book, I will lend it to you. (误)
If I had the book, I shoul lend it to you. (正)
如果我有书的话，我会借给你的。
IX. 条件从句不能用would，否则就算语病。
If he would have come yesterday, I should have told him. (误)
If he had come yesterday, I should have told him. (正)
如果他昨天来的话我会告诉他的。
注：如果表示有某种愿望，条件状语从句也可用would，相当于be willing to, 常表示说话人不相信主语有这种愿望。
If he would lend me the money, I would buy a car. (But I know he will not be willing to)
要是他愿意借钱给我，我就买一辆车。
If you would, you could.
要是你愿意的话，你能够做到。
②错综时间条件句
在错综时间条件句中，虚拟条件从句和主句动作发生的时间不一致，因此，主句和从句的谓语动词要根据各自所指的不同时间选用适当的虚拟语气形式。If he had listened to me, he would not be in such trouble now.
如果他当时听了我的话，现在就不会遇到这样的麻烦了。(过去→现在)
说明：从句的动作与过去事实相反，主句的动作与现在或现在正在发生的事实不符。
If he were leaving, you would have heard about it.
如果他真的要走，你早就听到消息了。(现在→过去)
If Echo should arrive today, she might have started 2 days ago.
如果艾蔻今天到达的话，那么她也许在两天前就动身了。(将来→过去)
③含蓄条件句
有些句子中，没有任何表示虚拟语气的词/短语/从句，但仍要用虚拟语气。这
时，要么是省略了表示虚拟语气的部分，要么是隐含在上下文中。
In the old days she would have argued.
要是在过去她早就争论了。
Anybody else would have believed you.
要换上别人早就信了你的话。
But for my money that woman would have persecuted him.
要不是我花了钱那女人早就找上他的麻烦了。
注：
but + 表示条件的结构：
would + 动词原形+ but/except + 现在时的陈述句(陈述语气)
→表示同现在事实相反的假设
would have + 过去分词+ but/except + 过去时的陈述句(陈述语气)
→表示同过去事实相反的假设
I would have gone with her but I was too busy.
我太忙了，不然的话就和她一起去了。
but that结构可以放在句首，并可换为but for + 名词结构，but则不可。But that it snowed heavily, they could have arrived there earlier.
= But for the heavy snow, they could have arrived there earlier.
要不是下大雪，他们还能早点儿到那儿。
But that I saw it, I couldn’t have believed it.
要不是亲眼所见，我是不会相信的。
3.虚拟语气用于从句
①主语从句、表语从句、同位语从句
A.It is
necessary/importan/strange/natural/essential/urgent/insistent/vital/advisable /preferable/better/pitiful/imperative/resolved/anxious/concerned/keen/fitting /obligatory/eager/ridiculous/appropriate/desirable/unthinkable/proper/good /right that…; It is requested/suggested/desired/proposed that…; It is a pity that…等结构(It is + 形容词/过去分词/名词+ that从句；有些词要用于I am + 形容词+ that从句)中，that引导的主语从句要用虚拟语气：(should) + 动词原形。
It is important that we should speak politely.
我们说话要有礼貌，这是很重要的。
It was proposed that this matter be considered at the next meeting.
有人提议这事下次会议再讨论。
It is his desire that a doctor should stay here.
他希望有一个医生留在这里。
It’s a pity that you should miss a good chance.
你竟然错过了一个好机会。(虚拟语气)
It’s a pity that you missed a good chance.
你错过了一个好机会，真遗憾。(陈述语气)
It seems so unfair that this should happen to me.
我身上竟发生这样的事，这似乎很不公平。
It’s strange that she should be so late.
真奇怪，她竟然来得这么晚。
说明：上述结构中，谓语动词用虚拟语气表示说话人的惊奇、懊悔、失望等感情色彩，常含有“竟然”之意，表示一种不可思议的状况，should一般不可省略。若用陈述语气也可以，但不带感情色彩。
I am surprised that he should have been so rude to you.
我很吃惊他竟然那么粗鲁地对待你。
They are especially anxious that you should come.
他们特别期盼你能来。
They were insistent that we be ready.
他们坚持要我们做好准备。
B.在advice, demand, order, idea, plan, proposal, suggestion, request, necessity,
resolution, decision, requirement, remmendation, preference, motion, desire, sentence等名词后的表语从句或同位语从句中，谓语动词用虚拟语气：(should) + 动词原形。
Our decision is that the school (should) remain closed.
我们的决定是学校暂不开学
The sentence is that the murderer (should) be shot.
判决枪毙谋杀犯。
My suggestion is that we (should) take the 7:00 train.
我的建议是搭乘七点的火车。
He made the suggestion that they carry on the conversation in Chinese.
他建议他们用汉语接着交谈。
They express the wish that they be given more free time.
他们表示希望给他们更多的空闲时间。
The resolution that women be allowed to join the society was carried.
允许妇女加入该协会的决议通过了。
②宾语从句
A.wish后的宾语从句
wish 之后的宾语从句表示一种没有实现或根本不可能实现的愿望时，常用虚拟语气。
I wish I had more time.
但愿我有更多的时间。
I wish I could help you.
但愿我能帮助你。(但我不能)
She wished she hadn’t done it.
她希望她没做那件事。(后悔做了)
I wish you would go with me tomorrow.
但愿你明天跟我一块儿去。
B.
would rather, would prefer, would sooner, would as soon, would just as soon 等后的宾语从句
上述词组表示与客观事实不相符的愿望时，其后的宾语从句中的谓语动词要用虚拟语气。
I would rather you told me the truth.
我宁愿你给我讲真话。(现在)
I would sooner she painted the wall green next time.
我宁愿她下次把墙涂成绿色。(将来)
I would prefer you had seen the film yesterday.
我倒希望你昨天就看了这部电影。(过去)
注：
I. 上述词组后接动词原形，指现在或将来时间，表示一种主观愿望或选择。
I’d rather do it today.
我想今天做这件事。
He would sooner die than surrender.
他宁愿死也不愿投降。
He’d rather not go dancing tonight.
他今天晚上不想去跳舞。
II. 上述词组后接不定式的完成式，表示过去的某种选择不恰当。
I’d rather have stayed at home than went to the dull film.
我倒宁愿待在家里而不去看那部无聊的电影。
I’d rather not have told her he news. She is such a gossip.
我不想告诉她这个消息，她可是个爱说闲话的人。
C.would rather… than…, would… rather than…
上述词组后的句子要用虚拟语气：than后的从句要用should + 动词原形，than后的从句可用that引导，有时that可省略。
She would rather die than (that) he should know the secret.
她宁愿死，也不会让他知道那个秘密。
He’d do anything rather than (that) he should live with such a shameless woman.
他宁死也不愿同这样一个无耻的女人生活在一起。
D.表示“建议/愿望/请求/命令”等词后的宾语从句
suggest, propose, advise, recommend, insist, persist, intend, expect, determine, desire, decide, demand, ask, beg, request, promise, conscent, petition, move, command, order, direct, require, argue, maintain, dictate, decree, vote, urge, provide, specify, appoint, arrange, stipulate, resolve, deserve (值得提及), prefer, instruct, advocate, persuade, agree (决定), pray (恳求), legislate (立法), sentence, object (反对), permit, 上述意念动词/祈使动词/态度动词后的宾语从句要用虚拟语气：(should) + 动词原形。(说明：美国人多用动词原形；
英国人过去多用should + 动词原形，但现在用原形的人也越来越多)
They urged that the library be kept open during the vacation.
他们极力主张放假期间图书馆继续开放。
She demanded that I pay her immediately.
她要求我立即付款。
I advise that he go at once.
我建议他马上去。
Congress has voted that the present law be maintained.
国会投票决定维持现行法律。
I move that we accept the proposal.
我提议通过这项提案。
注：当suggest表示“暗示，表明”；insist表示“坚持认为”，而不是“坚决要求”时，其后的从句要用陈述语气。
Her pale face suggested that she was ill.
她苍白的面容表明她病了。
He insisted that he heard somebody in the house.
他坚持说他听见房子里有人。
E.imagine
imagine表示现在/将来非现实情况的意想用were型结构，表示对过去非实际情况的意想用had + 过去分词结构。
Imagine that we were on desolate island now.
设想一下我们现在一个渺无人烟的荒岛上。
③目的状语从句
在in order that, so that引导的目的状语从句中，谓语动词多用：should/would/could/might + 动词原形来表示虚拟；而在lest, in case, for fear 等引导的目的状语从句中，谓语动词多用：should + 动词原形来表示虚拟，表示忧虑或目的，should有时可省略。
I hired a boat so that I could go fishing.
我租了一条船以便能出去钓鱼。
Please remind me of it tomorrow in case/lest I should forget.
请你明天再提醒我这件事，以免我忘记。
注：若in order that, so that前的主句是现在时，其后的从句有时也可用: can/may + 动词原形。
Ask her to hurry up with the letters so that I can sign them.
让她赶紧把信件拿过来我好签字。
④方式状语从句
as if, as though引导的方式状语从句中常用虚拟语气。
He behaves as if he owned the place.
他表现得像是这地方的主人。
He talks as though he knew where she was.
他谈起来仿佛知道她在哪儿似的。
The two strangers talked as if they had been friends for years.
这两个陌生人谈论着，好像他们是多年的朋友似的。
It looks as if it might rain.
看上去好像要下雨。
注：
I. as if, as though后面的从句有时也可用陈述语气，这时从句中的情况往往是可能发生的或可能被设想为真实的。
II. 主句谓语动词是look, seem, taste, smell, 从句可以用陈述语气。
The meat tastes as if it has gone bad.
这肉吃起来似乎已经坏了。
It looks as if they are in a hurry.
看起来他们好像很忙。
It seems as if we shall have to walk.
看上去我们得步行了。
The milk smells as if it is sour.
这奶闻起来好像酸了。
III. as if, as though还可引导表语从句。
It isn’t as if you were going away for good.
又不是你一去不复返了。
It is not as though he were poor.
直译: 他不像穷的样子。
意译: 他才不穷呢。/他又不穷。
You look as if you didn’t care.
你看上去好像不在乎的样子。
IV. as if前的主句有时可省略。
As if he were a teacher.
好像他是个老师似的。
As if he had seen a ghost.
他好像见了鬼似的。
V. than后有时可跟由if引导的虚拟条件句。
I can learn more from his words than (I could learn) if I had read ten books.
我从他的话中所学的东西比读十本书学得东西还多。
He feels happier in living alone than (he would feel) if he were living with his family.
他自己独住比同家人一起住更愉快。
⑤让步状语从句
even if, even though引导的让步状语从句，若表示与事实相反，可用虚拟语气，主从句的结构与if引导的条件从句结构相同；若表示事实，even if, even though引导的从句谓语动词用陈述语气。
Even if/though I were rich, I would work.
即使我很富有，我也要工作。
Even if he were here himself, he should not know what to do.
即使他亲自来也不知该怎么办。
注：
I. 有些让步状语从句中，特别是某些句型中，要用现在虚拟语气，即从句谓语动词用动词原形，表示推测、让步等含义，但主句一般用陈述语气。Whatever be the reason, he refuses to sign his name to the document.
无论是什么理由，他拒绝在文件上签字。
Whether she right or wrong, we will support her.
不管她是对还是错，我们都会支持她。
The business of each day, be it selling goods or shipping them, went quite smoothly.
不论是卖货还是运货，每天的生意都进展得很顺利。
II. 有些让步状语从句中，特别是某些句型中，用may, might, would等构成谓语，但主句一般用陈述语气。
Come what may, we are not going to make any concessions to his unreasonable demands.
不管怎样，我们都不准备对他的无理要求做出任何让步。
Be that as it may, we have nothing to lose.
即使如此，我们也不损失什么。
However dangerous it might be, I would have a try.
不管多危险，我都要试一试。
Poor though you might be, you can not live all your life on charity.
尽管你很穷，你也不能一辈子靠救济过日子。
Try as I would, I can not ask him to follow my advice.
不管想什么办法，我都不能要求他按我的意见行事。
⑥原因状语从句
amazed, angry, annoyed, astonished, happy, pleased等表示情感的形容词后面的状语从句中常用“should + 动词原形”表示虚拟语气，“should + 动词原形”指现在，意为“竟然”。
He is angry that you should call him by name.
他很生气，你竟然直呼其名。
⑦定语从句
It is high time…/It is about time…/It is time…句型要用虚拟语气：谓语动词用过去式，指现在或将来的情况，表示“早该干某事而已经有些晚了”；此种结构中的过去式也可改为：should + 动词原形( should不能省略)，但不如用过去式普通。
It is high time that we went.
是我们该走的时候了。
It was time I was in bed.
我该上床睡觉了。
It is time we went to bed.
= It is time we shoud go to bed.
= It is time for us to go to bed.
我们该就寝了。
4.虚拟语气特殊用法
①if only, would that引导的条件句
if only, would that后用虚拟语气，谓语动词用一般过去时表示现在没有实现的愿望(与现在事实相反)；用过去完成时表示过去没有实现的愿望(与
过去事实相反)；用“would/could + 动词原形”表示将来，常意为“要是……
就好了”。
If only I could speak several foreign languages!
我要是能讲几种外语就好了！
Would that I were young again.
但愿青春重在。
If only she had known where to find you.
她要是知道到哪里去找你就好了。
②祝愿语
在一些表示祝愿的感叹句中，用动词原形，表示愿望。
God be praised!
愿上帝受到赞美！
The lord save us!
愿主救我们！
Long live peace!
和平万岁！
So be it.
就这样把。
May you be happy!
祝你快乐！
May there never be another world war.
愿永远不再有世界大战。
③What if…
What if… 意为“要是……怎么办”“要是……将会怎么样”，从句中的谓语动词
用“should + 动词原形”或一般过去时表示虚拟语气。
What if it should rain?
如果下雨怎么办？
What if I should fail?
万一失败了，我该怎么办呢？
④as it were
as it were (were就是虚拟语气)，通常插在句子中间，意为“姑且这么说”。
He is, as it were, a walking dictionary.
他可说是一部活字典。
⑤would have thought
would have thought本身就是虚拟语气，意为“会想到”“会以为”等。
Who would have thought to see you here!
谁会想到在这里见到你！
You would have though they would do more to help us.
你原本会以为他们会更多地帮助我们的。
⑥suppose that, supposing that
两者表示非真实条件时，用虚拟语气，表示对现在或将来的假设；表示真实条件时，用陈述语气。
Suppose/supposing that there were no gravitational force, objects would not fall to the ground when dropped.
如果没有地心引力，物体下落时就不会掉到地上。(对现在情况的假设) Suppose/supposing that it rained, we shouldn’t go out.
要是一会下雨了，我们就不出去了。(对将来的假设)
Suppose/supposing that it rains, we wo n’t go out.
如果下雨的话，我们就不出去了。(下雨的可能性大)
⑦unless
unless可以引导真实条件句，也可以引导非真实条件句。
I couldn’t get a grant unless I had five years’ teaching experience.
= If I did not have five years’ teaching experience, I couldn’t get a grant.
如果没有五年的教龄，我就得不到补助金。
Unless you had done it earlier, you would have failed.
= If you had not done it earlier, you would have failed.
要不是你做的早，你就失败了。
⑧in case
in case引导的句子可用陈述语气，也可用虚拟语气：(should) + 动词原形。
The games will be postponed in case it snows.
要是下雪的话我们就推迟比赛。
The games will be postponed in case it (should) snow.
要是下雪的话我们就推迟比赛。
说明：in case it snows比in case it (should) snow可能性大些。
⑨祈使句+ and + 陈述句
该结构中的祈使句相当于if引导的条件从句，陈述句既可以表示真实条件；也可以表示非真实条件，此时要用虚拟语气。
One more step forward and you will touch it.
再向前一步，你就碰到它了。(真实条件)
One more step forward and you would have touched it.
当时要是再向前一步，你就碰到它了。(非真实条件)
⑩名词词组+ and + 陈述句