一、省略连词if 采用倒装的非真实条件句

在书面语中，条件从句可以不用连词if, 而将谓语中的过去式were,had或should等移至主语之前，构成倒装。

例：Were you in my position, you would do the same.

假如你处在我的地位，你也会这样干的。

例：Had he come earlier, he would have met her.

要是他早点来的话，他就会见到她了。

二、虚拟语气在储蓄条件句中的应用

非真实条件句中的条件从句有时不表示出来，只暗含在短语或上下文中，这种句子叫做储蓄条件句。常见的有but,for ,without等引导的短语，以及or, or else, otherwise, but 等后面的分句。

例：But for your help we couldn’t have succeeded in the experiment.

如果没有你的帮助，我们的实验室是不会成功的。

例：We could have done better under more favourable conditions.

在更有利的条件下，我们能够做得更好些。

经典考题：

1、____right now, she would get there on Sunday.

A)Would she leave

B)If she leaves

C)Were she to leave

D)If she had left

2、____for my illness I would have lent him a helping hand.

A)Not being

B)Had it not been

C)Without being

D)Not having been

3、We didn’t know his telephone number, otherwise we ____him.

A)would have telephoned

B)must have telephoned

C)would telephone

D)had telephoned

4、A safety analysis____the target as a potential dandger Unfortunately, it was never done.

A)would identify

B)will identify

C)would have identified

D)will have identified

解析：

1、答案选C。从句子结构可知，本题是表示与将来事实相反的虚拟语气。主句的谓语是“should+动词原形”。同时，从句省略了连词if, 可以将were提前，构成倒装。只以C符合语法规则。本题意思：如果她马上动身的话，她可能在星期天到达那里。

2、选B。从句子结构可知，空缺处应填入表示与过去事实相反的虚拟条件从句，并且将连词if 省略。此时应把虚拟语气的谓语动词提前。符合语法规则的只有B项。

3、选A。本题中otherwise引出的是一种与事实相反的假设条件，后面的句子应用虚拟语气。前一分句暗示了一个过去的时间，所以用不着would have done的形式，相当于If we had known his telephone number, we would have telephoned him.

4、选C。根据unfortunately后面直接陈述一个过去的事实，可以推断出第一个句子里含有一种“应该做某事而没有做的”虚拟条件。C项用于表示与过去事实相反的虚拟语气，正合题意。B、D不是虚拟语气。