3、在“开放式条件句”（open conditional clause）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。如：

　　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

　　4、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.

　　六、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）

　　第二节：其他形式的条件句中的虚拟语气

　　一、用“without/but for/in the absence of ”表示“要不是”，“如果没有”（相当于if it were not for…）表示条件时，句中一般用虚拟语气。（也可用陈述语气）

　　Without your help，I couldn' t finish my work on time.

　　In the absence of water and air，nothing could live.

　　二、由“providing （that）/ provided （that）/on condition that/ in order that“引导的条件从句或目的从句，根据情况，可用虚拟语气。（有时也可用陈述语气）

　　They are willing surrender provided they are given free passage.

　　三、用without / but for / in the absence of 表示"要不是"、"如果没有"，表示条件虚拟句：

　　（1）、Without air，nothing could live.要是没有空气，什么也不能生存。

　　（2）、But for your assistance，we could not accomplish it.要不是你的帮忙，我们是难有成就的。

　　（3）、In the absence of water and air，nothing could live.如果没有水和空气，什么也不能生存。

　　第五部分：其他几种情况下的虚拟语气

　　第一节：虚拟语气在as if / as though 引导的方式状语从句中的应用

　　虚拟语气在as if / as though 引导的方式状语从句中，谓语动词形式与wish后的宾语从句基本相同

　　1.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：

　　（1）、.He felt as if he alone were responsible for what had happened.他感到仿佛唯独他要对发生的一切负责。

　　（2）、He acts as if he were / was a TV expert.他做起事来好象是个电视专家。

　　（3）、Alan talked about Rome as if he were a Roman.艾伦谈起罗马来好像他是个罗马人一样。

　　（4）、John pretends as if he didn' t know the thing at all，but in fact he knows it very well.（用过去式表示与现在事实相反的假设）

　　（5）、He pretends as if he didn't know the thing at all，but in fact he knows it very well.（用过去式表示与现在事实相反的假设）他假装好象完全不懂那事，其实他对那事非常了解。

　　2. 表示过去想象中的动作或情况，谓语动词用过去完成式。如：

　　（1）、The tree looked as if it ______ for a long time.

　　A. hasn't watered 　　　　B. didn't water

　　C. hadn't bee watered 　　D. wasn't watered

　　那棵树看上去好象很久没人给浇水了。（答案是c）

　　（2）、The old man looked at the picture，he felt as though he had gone back to time 20 years ago.（用过去完成式表示与过去相反的事实）

　　（3）、The old man looked at the picture，he felt as though he had gone back to time 20 years ago.（用过去完成式表示与过去相反的事实）那老人看着照片，他觉得仿佛回到20年前的时光。