常见的虚拟语气句型
1．if条件句
条件状语从句可分为真实条件句，即条件满足，事实就发生的情况；和非真实条件句，即与事实相反或难以实现的假设情况。虚拟语气的基本句型，即是这种非真实条件状语从句。其具体形式如表中所示：
| 条件从句谓语 | 主句谓语 |
与现在事实相反 | 动词过去式(动词be用were) | would/should +动词原形 |
与过去时间相反 | had + 过去分词 | would/should + have +过去分词 |
| 动词过去式(动词be用were) | |
将来不大可能发生的事 | 或 should +动词原形 因此英语 | would/should +动词原形 |
| 排卵期是哪几天或 were +动词不定式 | |
| | |
If I knew English, I would go abroad to further my study.
If I had got up early, I wouldn’t have been late.
If I were to do it, I should do it at once.
【说明】
①在非正式英语中，条件从句中的第一、第三人称单数主语后可用was代替were。
If I was you, I would accept the invitation.
②主句中的would可用于各种人称，而should只用于第一人称。
③在主句中也可用情态动词could，might代替would，should。
If I had had enough time, I might have done it better.
④条件从句中的谓语动词含有were，had，should时，可以省略从属连接词if，然后采用倒装结构，把were，had，should移到主语前面。
Should you pass this way, do drop in for a visit.= If you should pass this way,……
Had I known it, I wouldn’t had made such a silly mistake.= If I had known it,……
Were it left to me to decide whether I should have a job immediately or go on to study at college, I wouldn’t hesitate a moment to choo the latter.= If it were left to me to decide……..
⑤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。
[误]If my grandfather comes tomorrow, I should stay home.
[正]If my grandfather comes tomorrow, I shall stay home.
[正]If my grandfather were to come tomorrow, I should stay home.
⑥有时，条件和结果发生的时间不一致，动词形式便要作适当调整，变成错综时间条件句。
If you had taken the medicine, you would be well now.
If he were honest, he would had told us the truth.
If it hadn’t rained so much, we would have a good harvest in autumn.
2．介词或介词短语without/ thanks to/ but for +名词结构代替if条件句表示的虚拟语气。
| 主句谓语 |
与现在事实相反 | would/should/could +动词原形 |
与过去时间相反 | would/should/could + have +过去分词 |
将来不大可能发生的事 | would/should/could +动词原形 |
| |
But for your help, I could sit here and prepare for my mid-term examination.
Thanks to the man’s timely rescue, the child would have been drowned.
Without the sun and water, nothing would live.
3．wish +宾语从句
| 宾语从句谓语 |
与现在愿望相反 | 一般过去式(动词be用were) |
与过去愿望相反 | had +过去分词 |
将来不大可能发生的愿望 | would/should +动词原形 惊蛰是什么意思啊 |
| |
I wish I were as strong as you.
I wish I had not failed the chemistry examination.
I wish I would become a pilot when I grow up.
*hope与wish不同，后面接宾语从句一般表示真实情况，其愿望一般可以实现。
I hope it will be fine tomorrow.
但如果说had hoped，则表示一种过去未实现的愿望，宾语从句用would +动词原形来表示。
I had hoped Tom would attend the meeting.
4．it’s (high) time +从句
| 从句谓语 |
表示是应该做某事的时候了 | 动词过去式/ should +动词原形 | 中药三七
| |
It’s time we got something to eat.
5．as if或as though +方式状语从句
万圣节要糖果 | 主句谓语 | 从句谓语 |
与现在事实相反 | | 动词过去式(动词be用were) |
与过去时间相反 | 非虚拟情况 | had +过去分词 |
与可能发生的事相反 | | would/should +动词原形 |
| | |
He speaks as if he were the manager.超级班长
He talks as if he had been on the spot.
The situation ems as if it would be out of control.
6．if或if only表示愿望
| 从句谓语 |
与现在事实相反的愿望 | 人财两空动词过去式(动词be用were) |
与过去事实相反的愿望 | had + 过去分词 |
将来不大可能发生的愿望 | would +动词原形 |
| |
If I were with you now!
If only I had not been that silly!
If only the rain would stop!
高山蔬菜 *此句型大多可与wish句型转换。如上面三句分别相当于：
I wish I were with you now.
I wish I had not been that silly.
I wish the rain would stop.
7．suggest, require, order, etc. +宾语从句
在一些表示建议、愿望、要求、请求、劝告、意志、欲望、命令、安排、决定等的动词的宾语从句中，要用虚拟语气。其形式是should +动词原形。肯定句式中should可以省略，而仅用动词原形。这类动词有：ask，require，request，demand，pray，insist，desire，maintain，propo，suggest，move，urge，advi，recommend，command，order，arrange，decide等。
She demanded (that) the paper (should) be rewritten.
I suggest (that) he (should) get there as soon
8．it is important, required, etc. +主语从句
在it is +表示要求、建议、必要、命令等意思的形容词或分词+主语从句的结构中，要用should +动词原形的虚拟语气，should可省略。这类形容词和分词有：advid，advisable，better，desired，desirable，demanded，esntial，important，natural，necessary，ordered，propod，possible，probable，preferable，recommended，required，suggested，strange，urgent，strange，incredible等；这个表语结构也可以是it is a pity，it is a wonder，it is a shame等。
It’s necessary (that) we (should) start to do the work right away.
It’s urgent we (should) nd for a doctor at once.
It is a pity that she (should) call black white.
9．用于表语从句或同位语从句中的虚拟语气
在一些表示愿望、建议、要求、命令等意义的名词后的表语从句或同位语从句后，谓语动
词要用虚拟语气。这类名词有：advice，decision，idea，order，plan，proposal，recommendation，suggestion，opinion，requirement，direction，policy等。
My opinion is that we (should) review their proposal right now.
He made the request that the problem (should) be ttled at once.
10．Lest/ for fear (that)/ in ca 引导的状语从句
这类状语从句表示担心、忧虑，谓语动词用(should) +动词原形构成。
I’m telling you this lest you (should) doubt my sincerity.
Julia had to go on a diet for fear that she (should) lo her job as a model.
11．in order that, so that +目的状语从句
We started our journey before dawn so that we might stand a chance to reach there before sunt.
