牙齿脱落多久镶牙:初中英语

虚拟语气

有些条件句是可能实现的,称为真实条件句. 虚拟语气是动词的一种特殊形式,用来表达说话人的意愿.请求,设想,等未能或不可能实现的事实,或说话人看来实现可能性很小的情况.做这类题时首先要弄清楚虚拟语气的各种句型,即由if引导的虚拟条件句,省略if的倒装形式,可跟虚拟语气的宾语从句,同位语从句,表语从句的句型,以及表示祝愿或感叹的句子和由without, but for等介词引导的短语或句子.

四级对虚拟语气的测试主要涉及以下方面:

1). 主语从句,同位语从句中虚拟语气的用法.

2). 宾语从句中虚拟语气的用法,尤其是wish 虚拟语气结构的用法.

3). If条件句中虚拟语气的用法,应特别注意省略if的倒装结构是考试的重点.

4). would rather 等结构中虚拟语气的用法.

5). if only结构中虚拟语气的用法.

6). But, or, otherwise 等含蓄条件句的用法.

7). It’s time (that) 等结构中虚拟语气的用法.

1. 虚拟语气在虚拟条件句中的运用

(1)虚拟语气现在时. 用以表示与现在事实相反的假设或现在实现可能性不大的情况.

条件从句
主句

动词过去式(be多用were)
Would/should/could/might + 动词原形

Eg. If I were a bird, I would fly to you.

If it were not for their help, we should be in a very difficult position.

(2) 虚拟语气过去式. 表示与过去事实完全相反的假设.

条件从句
主句

had + 过去分词
would/should/could/might + have +过去分词

Eg. If we had started earlier, we should not have missed the train.

If she hadn’t been ill, she might have come.

(3)虚拟语气将来式. 表与将来情形相反的假设或极少有可能实现的情况.

条件从句
主句

动词过去式或should +动词原形或were to +动词原形
would/should/could/might +动词原形

Eg. If Professor Li should have time tomorrow, we could ask him some questions.

If there should be no air, there would be no living things.

◆ 书面语中,上述(1),(2),(3)三种时态的虚拟句中,如果从句里含有should, had, were或其他助动词,则可将从属连词if省去,将助动词.情态动词.be或have放在句首形成部分倒装.

Eg. Were he in your position, he’d have done the same.

Had I had time, I would have done that yesterday.

Should he come tomorrow, I should give him the dictionary.

(1) 错综时间虚拟句

通常情况下,在非真实条件句中主句和从句的谓语动词所指时间是一致的, 但有时也可能指不同的时间,这时要根据上下文的意思采用不同的谓语动词形式. P 116, 2

Eg. If I were you, I would have taken his advice. (从句指现在, 主句指过去)

If I had taken my raincoat with me this morning, I would not be wet now. (从句指过去,主句指现在).

(2) 含蓄条件句

有时假设的情况并不以条件从句表示出来,二是暗含在上下文中,比如通过介词短语来表示.

Eg. But for your advice, I could not have done it so successfully.

The change could not have taken place without the open-door policy.

I was so busy then, Otherwise, I would have told him the answer.

(3) 虚拟语气在某些从句中的应用.

A) 在wish, suggest, order, demand, propose, command, request, recommend, require, decide, insist, desire, urge等动词的宾语从句以及would rather /sooner 后要用 “ (should) +动词原形” 来表示愿望,建议, 命令,要求等; 由上述动词派生或转化的名词suggestion, proposal, plan, motion, recommendation, demand, order, desire, request, requirement, insistence, advice, decision , obligatory 义不容辞的, 必须的 等的同位语从句或表语从句中也要用相应的虚拟形式.

Eg.

B) 在It is/was + 某些形容词 + that 从句的句型中,that从句中的谓语动词常用虚拟语气,即 “should + 动词原形”

这些形容词有:

important, necessary, essential, imperative, natural, strange, advisable, desirable, possible, probable, astonishing, surprising, desired, suggested, requested, recommended, ordered, proposed, decided, moved等.

“ should + 动词原形(或完成形式)” 可表示惊奇,遗憾,怀疑,不满等.

ⅰ. 用于expect, believe, think, suspect 等动词的否定或疑问形式后的宾语从句中.

Eg. I never expected that the new apartment should be so small.

ⅱ. 用于 “It is a pity, it is a shame, it is no wonder 等 + that” 等结构后的主语从句中.

Eg. It is a pity that he should be so careless.

C) 在由for fear that, in case, lest 等引导的状语从句中,用 “ should + 动词原形” 表示 “惟恐”的意思.

Eg. He handled the instrument with care for fear that it should be damaged.

D) 在 “ It is (about/ high ) time + that (从句)” 中,谓语动词常用过去式表表示虚拟语气.

Eg. It is high time that people learnt English.

E) 在 “as if/ as though” 引导的状语从句中,谓语动词与wish的宾语从句的虚拟形式相同.

Eg. He works with such enthusiasm as if he never knew fatigue.

He speaks English as though he were an American.

F) 在 look, seem等动词后的 “as if / as though”从句中,当表示真实情况时,用陈述语气; 否则,用虚拟语气.

Eg. It seems as if they know each other. (真实情况)

It seems as though it were already spring. (虚拟语气)

G) 用在if only 引起的感叹句中.

Eg. If only the driver didn’t drive so fast!

虚拟语气
虚拟语气(Subjunctive Mood)这一语法项目是各类英语考试中心测试的重点之一。虚拟语气是一种特殊的动词形式，用来表示说话人所说的话并不是事实，而是一种假设、愿望、怀疑或推测。
Ⅰ用以表示虚拟条件的虚拟语气
⒈ 用if条件从句表示的虚拟条件，是虚拟条件最普通的方式。
① 虚拟现在时表示与现在事实相反的假设，其if 从句的谓语形式用动词的过去式(be 一般用were)，主句用would/ should/ could/ might +动词原形，例如：If I were in your position I would marry her.
② 虚拟过去时是表示与过去事实相反的假设，if 从句的谓语形式用过去完成时即had＋过去分词，主句用would / should / could / might + have +过去分词，例如：If it had not rained so hard yesterday we could have played tennis.
③ 大多数的虚拟条件句属于上面三种情况的一种，但并不排除存在条件和后果中，一个和现在情况相反，另一个和过去情况相反，例如：If you had followed what the doctor said, you would not have been so painful now.这个句子在高中出现频率颇高。
④ 但是，如果后果用了虚拟语气，而条件却用陈述语气，这种用法是错的。
⒉ 除了表示虚假条件外，if从句还可以表示对将来的推测，由于是将来还没有发生的，所以谈不上是真实的还是虚假的，只能说这个事情发生的可能性有多大。一般情况下，可以用陈述语气的if从句来表示对一个未来事实的推测，这个事实是完全可能发生的。If从句的谓语形式用一般过去式或用were to / should +动词原形，主句用would / should /could/ might +动词原形，例如：Jean doesn't want to work right away because she thinks that if she were to get a job she probably wouldn't be able to see her friends very often.（1996年1月四级第44题）
⒊ 有时可以把含有助动词、情态动词、be或have的虚拟条件句中的连词if 省去，而将had , should, were 等词提到主语之前，即用倒装结构,这时候，如果出现not等否定词，否定词需放在主语后面。这种结构在口语中很少使用，但频频出现在各类考试中出现，例如：If it had not rained so hard yesterday we could have played tennis.→Had it not rained so hard yesterday, we could have played tennis.
⒋ 大多数的虚拟条件通过上面所讲的两种方法表达，但在个别句子中也可以通过介词without和介词短语but for表达，副词otherwise等表达出来。例如：We didn't know his telephone number; otherwise we would have telephoned him.（1995年6月四级第46题）值得注意的是，包含but for的句子，谓语动词必定要用虚拟形式，但包含without等短语的句子，谓语动词未必一定要用虚拟语气。
⒌ 有时虚拟条件不是明确地表达出来，而在蕴含在用but引导的从句里，于是便出现了有谓语动词是虚拟语气的主句加上谓语动词是陈述语气的but从句构成的并列复合句，例如I would have hung you but the telephone was out of order.在这样的句子里，如果主句没有用虚拟语气，或者从句用了虚拟语气，都是错的。
Ⅱ用在宾语从句中的虚拟语气
⒈ 在表示愿望的动词wish后的宾语从句中，需用虚拟语气。（wish后的that 常省略），根据主句时态，从句谓语时态相应退后一位，例如：How she wished his family could go with him.
⒉ 在具有愿望、请求、建议、命令等主观意愿的动词(desire, demand, advice, insist, require, suggest, propose, order, recommend, decide …) 后的宾语从句中需用虚拟语气。谓语动词用(should) +动词原形。值得注意的是，如果宾语从句的动词是否定的，否定词not的位置应在动词之前，而不是动词之后。例如：The head nurse insisted that the patient not be move.另外，如suggest表达“暗示”，insist表示“坚持某种说法”时，后面的从句不用虚拟语气，例如：Her pale face suggests that she is ill.或He insisted that he did not kill the boy.
除此之外，上述动词也要求用虚拟式
① 在It is+上述动词的过去分词，其后所跟的主语从句中，如It is suggested that pupils wear school uniforms.
② 在上述动词相应的名词形式作主语+连系动词，其后的表语从句中，例如His suggestion was that classed be re-scheduled.
③ 在对上述动词相应的名词进行解释的同位语从句中，如：The workers raised the demand that their pay be increased to cope with the inflation.
⒊ would （had）rather , would sooner也用来表达主观愿望，它们之后的宾语从句中需用虚拟语气。谓语动词用过去式表示现在或将来，用过去完成式表示与过去事实相反，例如：I would rather he went right now.
Ⅲ其他形式的虚拟语气
⒈ it is +necessary等形容词后，that主语从句中虚拟形式使用，这类形容词包括necessary, important, essential, imperative, urgent, preferable, vital, advisable等，例如It is necessary that you listen to the teacher carefully.或者It is essential that you be able to pronounce every single word correctly.
⒉ 在It's (high/about) time 之后的定语从句中需用虚拟语气。谓语动词用过去式，例如It is high time that you went to school
⒊ 虚拟语气在as if / as though 引导的方式状语从句中的应用（谓语动词形式与wish后的宾语从句基本相同）表示与现在事实相反或对现在情况有怀疑，谓语动词用过去式。例如：He felt as if he alone were responsible for what had happened. 表示过去想象中的动作或情况，谓语动词用过去完成式。
⒋ 在lest 引导的状语从句中，谓语动词多用虚拟语气，(should )+ 动词原形。例如： The mad man was put in the soft-padded cell lest he injure himself.（1998年1月四级第38题）
⒌ 在if only 引起的感叹句中需用虚拟语气。谓语动词用过去式或过去完成式。例如： Look at the terrible situation I am in! if only I had followed your advice.