虚拟语气：与事实相反的

一、 if从句： 即 主句……， if 从句……

1、倒装代替if从句：Had\Were\Should ……，主句……

2、but for = without（如果不是）代替if从句， 两个都是介词

But for \without + 名词 ，主句……

3、with + 名词 ，主句 ……

4、if only + （if 从句） 要是……该多好

二、宾语从句：

1、I suggest（表示命令；建议；请求） that …… shoule +do……

（在虚拟语气中，shoule have done = ought to have done,其他时候should 不等于ought to）

2、I wish that ……（用虚拟语气）

三、主语从句：

1、it is +adj\n that + 虚拟

2、it is +done（表示建议、要求）that + 虚拟

四、目的状语：

Lest或者for fear that + （虚拟语气）should do

五、隐藏虚拟语气：本打算做但结果没有做的

1、had hoped\intended\planned\expected\wanted\meant to do

2、hoped to have done

3、be（was\were） + to have done

4、would\should like to have done

Would have done 表意愿、将来

Should have done 竟然做了、本应该做的

Could have done 有能力做

Might have done 表示猜测

Need have done 本来需要做的却没有做

六、主从句时间不一致情况下的虚拟语气

有时条件从句中的动作和结果与主句中的动作，发生的时间不一致，这时动作的形式应根据它所表示的时间加以调整。如：

1. 从句表示过去，主句表示将来：

⑴、 If they had started the early morning yesterday, they would be here now.

⑵、 If we hadn' t made adequate preparations, we shouldn' t dare to do the experiment next week。

2. 从句表示将来，主句表示过去：

⑴、 If I were not to make a preparation for my experiment this afternoon, I would have gone to see the film with you last night.

3.从句表示将来，主句表示现在：

⑴、 If we shouldn't have an exam this afternoon, I would go shopping now.

4.从句表示过去，主句表示现在。

⑴、 If they had stared the early morning yesterday, they would be here now.

⑵、 If you had followed my advice, you would be able to finish the work now.

6.从句表示现在，主句表示过去

⑴、 If I were you, I would have gone to her birthday party.如果我是你，我就去参加她的生日晚会了。 （从句说明现在，主句说明过去。 ）

7.从句表示过去，主句表示过去和现在

⑴、 If you hadn't lent me some money, I couldn't have bought the new house and most likely I would be still living in the dangerous house now.

在不少情况下，虚拟式已变成习惯说法，很难找出其暗含的条件。

（1） You wouldn't know. 你不会知道。

（2） I would like to come. 我愿意来。

（3） I wouldn't have dreamed of it. 这是我做梦也不会想到的。

（4） He told the story in such minute detail that he might himself have been an eye-witness. 他将那事讲的非常仔细，简直就象他亲眼看见一样。

条件从句中省略 if 采用倒装语序的情况

在 if引导的表示虚拟的条件状语从句中，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。

1）。 原句： If she were younger, she would do it.

去 If： Were she younger, she would do it. （把动词 were移到主语 she的前面 ）

2）。 原句： If he had tried it, he could have done it.

去 If： Had he tried it, he could have done it.（把 had移到主语 he的前面 ）

3）。Had he worked harder, he would have got through the exams.

4）。Were he to leave today, he would get there by Friday.

5）。Were I in your place, I wouldn't do that.

6）。Had I seen the film, I would have discussed it with them last night.

假如我看了那部电影，昨晚我就可以和他们一起讨论了。

7）。Were I a bird, I could fly freely.

假如我是一只小鸟，我就能自由翱翔。

8）。Should it rain next week the farmers would have a good harvest.

要是下周能下雨的话，农民们就能有个好收成了。

如果虚拟条件句中有 were, had或 should时，把它们放在 if的位置上 ;但是如果条件句中没有 were, had或 should不能用倒装。

⑴ Should it rain tomorrow, what should we do?　要是明天下雨的话，我们怎么办呢 ?

⑵ Were I you, I would have asked him for some advice.要是我是你的话，我就向他请教了。

⑶ Were he to do this work by himself, he would get a lot of money.如果他自己能够做此工作，他就会得到一些钱。

在 "开放式条件句 "和让步状语从句中 should是被省略了的。在这种情况下，如果 if省略，动词 be与主语的位置要倒装。

⑴ If any person be guilty of a crime, the court shall have the right to appeal. （任何人犯罪，法院有权起诉。 ）

Be any person guilty of a crime, the court shall have the right to appeal.

⑵ Whether she be right or wrong, she will have my unanswering support. （不管她是对还是错，我都会支持她的。 ）

Be she right or wrong, she will have my unanswering support.

⑶ ____ ,I will take her as my wife.

[A]Were she rich or poor

[B]Being rich or poor

[C]Be she poor or rich

[D]Whether is she poor or rich

注意：有时虚拟条件句并没来 if 从句表示出来，而是用介词短语 （otherwise, or, without, but for）、上下文或其它方式来表示。

⑴、 We didn't know his telephone number; otherwise we would have telephoned him.

⑵、 Without you help, I wouldn't have achieved so much.

⑶、 But for your help, I would not have succeeded.

有时虚拟条件句的从句或主句都可以省略其中一个：

1. I could help you. （只有主句 ）

2. If I had time. （只有从句 ）

3. She should have come to the meeting. （只有主句 ）

4. If he had much more money. （只有从句 ）