中学英语语法分类复习-虚拟语气.doc

二十. 虚 拟 语 气

一、语气的种类
语气有三种：陈述语气、虚拟语气、祈使语气。虚拟语气，表示说话人的假设、猜测、建议或愿望，而不表示客观存在的事实。虚拟语气可出现在单独的一个句子和所有从句中；虚拟条件可由从句、介词短语、分词、不定式、形容词、副词乃至于名词等表示。

二、虚拟语气在状语从句中的用法
1. if条件从句中的用法
①表示与现在事实相反的假设
从句谓语动词用过去式（be动词的过去式正式用法一律用were），主句动词用“would/should/could/might +动词原形”。
If I were rich, I would buy that car.
若我有钱，我就买那辆车。
If I had a car, I should be very happy.
若我有一辆车，我会很快乐。
If you asked him, he might tell you.
如果你问他，他会告诉你。
★在虚拟语气中，should, would, could, might的区别：主句中，一人称可用would,也可用should,没有意义区别。前者表“肯定、必然”的结果，后者主要用于英国并可表“应该”含义。could表“能力、允许、可能性”，might仅仅表“可能性”，且语气弱。
②表示与过去事实相反的假设
从句谓语动词用过去完成式，主句用“should / would / could/might + have +过去分词”
If I had known her telephone number, I would have called her.
如果我知道她的电话号码，我就给她打电话了。
If he had hurried, he could have caught the train.
如果他抓点紧的话，他就会赶上火车了。
If he had been there, he would have helped you.
如果他在那儿的话，他会帮助你的。
③表示与将来事实相反的假设
从句谓语动词除用过去式（be动词用were）以外，还可用“should +动词原形”或“were to +动词原形”；主句用“would/should/could/might +动词原形”。
If I were to go abroad, I would go to America.
如果我出国的话，我就去美国。
If I saw him tomorrow, I would pass your note to him.
如果我明天看到他的话，我就把你的便条给他。
If it should rain tomorrow, I might get lost.
如果明天下雨的话，我可能会迷路。
④混合条件句：主句与从句的动作发生在不同时间，这时主、从句谓语动词的虚拟语气形式必须按其自己的时间来决定动词的形式。
If she hadn't trained so hard, she wouldn't be able to run so fast.
如果她以前训练没有这么刻苦的话，她现在不可能跑那么快。（从句与过去事实相反，主句与现在事实相反）。
If he had died in the accident, he couldn't stand in front of you now.
如果他在那次事故中死去，现在就不会站在你面前。

⑤省略if的虚拟条件从句的用法
如果条件句的从句部分含有系动词were或助动词should或had，有时可将if省略，把were, should或had移到主语之前。
Were I you（=if I were you）, I would get up early in the morning.
我是你的话，我早晨就会早起。
Had you arrived at the station ten minutes earlier yesterday(=If you had arrived…）, you could have caught the train.
昨天你早到车站十分钟的话，就会赶上火车了。
Should it rain（= If it should rain）, the crops would be saved.
要是下雨的话，庄稼就会得救了。
2.在in case, for fear (that), lest等引导的目的状语从句中，常用虚拟语气：谓语动词用should+动词原形，表示“唯恐，以免”。
She took the raincoat with her in case /for fear that /lest she (should) be caught in the rain.
The student is working hard for fear that he should fail the exam.
3.在so that, in order that引导的目的状语从句中，谓语常用虚拟语气，即may/might或can/could+动词原形。
Please speak much louder so that the students may hear you more clearly.
I lent him my bike in order that he could save some time.
三、虚拟语气用于主语从句中：
1.“It is necessary that···”这个句型中，表示情绪、观点的形容词或名词作表语，that引导的主语从句中谓语动词用（should） +V原形。常用的这类形容词、名词有：necessary, important, probable, possible, impossible, natural, strange, surprising, proper（适当的），urgent（紧迫的），vital（至关重要的），advisable（合理的）， appropriate（合适的），crucial（紧急的），essential（必要的），incredible（惊人的），preferable（更好的）； pity, shame, advice, decision, desire, demand, idea, miracle, order, proposal, requirement, resolution（决心），suggestion, surprise, wonder等。
It is necessary that you (should) clean the room after work.
你在工作后打扫房间是有必要的。
It is important that we should ask advice of other people about our work.在工作中征求别人的意见很重要的。
It is strange that he（should）have left without saying good-bye.
他离开时没有说再见是很奇怪的。
2. “It is ordered/suggested that...”在这一句型中，主语从句中的谓语动词应用虚拟语气，即：（should）+V原形。适用于此句型中过去分词的动词有：advise, arrange, ask, command, comply（遵照），decide, order, suggest, propose, require, demand, request, insist, urge, desire, recommend等表建议、提议、要求、请求、命令、愿望等主观意向的词。
It is ordered that the cloth（should）be woven.
据指示，现在就应纺织布料。

四、虚拟语气在宾语从句中的用法
1. wish所带的宾语从句中的谓语动词必须是虚拟语气。
①表示对现在或对未来的愿望，谓语动词用一般过去时（be 用were），或“would/could+动词原形”。
I wish I were as young as you.我希望和你一样年轻。
I wish that I had a car.我希望我有一辆车。
I wish I could fly to the moon some day.
我希望有一天，我会飞到月球上去。
②表示对过去的愿望，谓语动词用过去完成式或“could +完成式”。
I wish that I had known that.我希望我了解过那件事
I wish I had passed the driving test.我希望通过驾驶考试。
★wish与宾从动词都发生在过去同一时间，则都用一般过去时。
2.在表示命令、建议、要求、主张、提议、坚持等的动词如：advise（建议），arrange（安排），command（命令），decide（决定），demand（要求），desire（期望），insist（坚持），intend(打算），order(命令），prefer（宁愿），promise（允诺），propose（提议），recommend(推荐），request（要求），require（要求），suggest（建议），urge（催促），vote（提议），urge(力劝)等后面的宾语从句中，谓语动词要用“should +动词原形”或直接用“动词原形”。（前者为英国用法）
We suggested that the meeting (should) be put off.
我们建议会议推迟。
I required that he (should) come to my office.
我要求他到我的办公室。
He insisted that you (should）be seated there.
他坚持让你坐在那儿。
注意①当suggest不表“建议”而表“暗示”、“认为”、“可能”等时，从句中的谓动不用虚拟语气。
Her expression suggested (that）she was angry.
她的表情暗示她生气了。
②当insist表坚持对已发生事情的看法时宾语从句不用虚拟语气。
He insisted that he hadn't stolen the money.
他强调说他没偷钱。

五、虚拟语气用于表语从句和同位语从句中
3.表示“建议、提议（suggestion, proposal）”,“命令（order）”,“要求（request, requirement)”主张、目的等名词的表语从句和同位语从句中，动词用（should）+V原形。这类名词常见的有：suggestion, proposal, motion（提议）,order, pray（恳求）,request, recommendation, requirement, idea, aim, wish, plan, demand, decision, preference, necessity（必要性）,resolution（决心）,desire等。
Our suggestion is that the meeting (should) be held at once.
我们的建议是会议应立刻举行。
His order is that the cloth (should）be woven right now.
他的指示是立刻纺织布料。
The suggestion that students should learn something practical is worth considering.

六．虚拟语气在定语从句中的用法
It is（high/about) time that后面的定语从句的谓语动词要用过去时（偶尔用should加动词原形，但should一般不省略）。
It is time that we planted trees there.
是到我们在那儿种树的时候了。
It is high time that we should plant trees there.
早该是我们在那儿种树的时候了。
＊Anyone who had married such a girl as she would have been regretful.谁娶了像她那样的姑娘都会后悔的。

七．虚拟语气在一些特殊句型中的用法
1．由as if/as though（好像）引导的表语从句和状语从句中，谓语动词用虚拟语气。与现在事实相反谓语动词用过去时；与过去事实相反用过去完成时；与未来事实相反用would+动词原形。
He remembers everything exactly as if it happened yesterday.
He looked as if he had been ill.他看上去像是生过病。
He talked as if he had been to Paris.
他谈起来好像他去过巴黎。
She looks as though she had known all the secrets.
她看上去像是已经知道了全部秘密。
注意 as if/as though从句表达真实的情况就要用陈述语气。
It looks as if it is going to rain. (真的就要下雨)
2. even if/though引导让步状语从句，从句中用may/might +动词原形, may或might可省略，表示与现在情况相反；从句用过去完成时，表示与过去情况相反。
类似的词还有though/as though/so long as/no matter wh-/ whatever/ whenever/whoever等。
However dangerous it might be, he would have a try.
无论多危险，他都要试一试。
Even though I had been very busy then, I would have helped you.
即使我当时很忙，我还是会帮助你的。
3. if only句型（要是…该有多好啊）：与现在事实相反，从句中用过去式；与过去事实相反，从句中用过去完成时；与将来情况相反从句动词用could/would+动词原形。
If only I could see him now.
要是我现在能看到他该有多好啊。
If only I knew the answer.要是我知道答案就好了。
If only I hadn't lost it.要是我没弄丢它就好了。
注意 该句型也可用于表真实条件句，表“如果···”，不用虚拟语气。
4. would rather/sooner, had rather和would(just)as soon后面接省略that的从句表愿望，用过去式表示现在和将来,用过去完成时表过去。意为“宁愿，但愿”。
I would rather you told me the truth now.我宁愿你现在告诉我真相。
I would rather nothing had happened.我真希望啥都未曾发生。（过去）
I would rather you came tomorrow.我宁可你明天来。（未来）
5.表示祝愿或诅咒的祈使句
May you succeed! 祝你成功！
God bless you! 愿上帝保佑你！
May you have a good time.祝你玩得愉快！
Be it so! 但愿如此！
So be it then! 那就这样吧！
Long live China! 中华人民共和国万岁！
6.含蓄的虚拟条件句
虚拟条件不一定总是用if等引出，还可以用介词短语、分词、副词、形容词、名词等均可。要认真体会虚拟语气的实质，从多个角度去理解含虚拟语气的句子。
①without /but for/ were it not for/had it not been for/except for/apart from等+名词，意为“要不是...”；with/ under+名词。主句用虚拟语气。
But for your mother's help we wouldn't have finished the work.
要不是你妈妈帮忙，我们不可能完成这项工作。
②but that + 现在时动词/过去时动词，主句用虚拟式。
But that you help him, he would fail.
若无你的帮助，他会失败的。
But that you helped him, he would have failed.
若无你的帮助，他早就失败了。
③连词or, but或otherwise
He would have given you more help, but he has been so busy.
Seize the chance, otherwise you would regret it.
He felt very tired yesterday, or he would have helped you.

④不定式短语
He would be stupid not to accept that offer.
如果他不接受那项建议，那真是愚蠢。
It would be a mistake not to help him.
不帮助他将是一个错误。
⑤分词短语
This same thing, happening in wartime, would amount to disaster.
如果这件事发生在战时，就会是一场灾难。
Given time, they would probably agree.
给以时间的话，他们会同意的。
⑥状语从句
Help was promised where it should become necessary.
要是需要的话，就答应给予帮助。