if 非真实条件句的倒装

　　虚拟条件句的从句部分含有 were，should 或 had 时，可省略 if，再把 were，should 或 had 移到从句的句首进行倒装。

　　例如：

　　Were they here now, they could help us. = If they were here now, they could help us.

　　他们现在要是在的话，就会帮助我们了。

　　Had you come earlier, you would have met him. =If you had come earlier, you would have

　　met him. 你来得早一点，就碰到他了。

　　Should it rain, the crops would be saved. =Were it to rain, the crops would be saved.

　　假如下雨，庄稼就有救了。