在引导虚拟条件句的时候，if在什么情况下会省略呢，一些学生还是存有疑惑，今天我给大家简单说明一下。（这可是高考语法中考核的一项核心内容，大家必须掌握的）

如果从句中有were, had, should,可以省略if,用倒装句式“were, had, should+主语”。如：

If I were at school again, I would study better.

= Were I at school again, I would study better.

If you had come earlier, you would catch the bus.

= Had you come earlier, you would catch the bus.

If it should rain tomorrow, we would not go climbing.

=Should it rain tomorrow, we would not go climbing.

注：若省略的条件句中的谓语动词是否定形式时，不能用动词的缩略形式。如：

我们可以说：Were it not the expense, I would go abroad now. 但不能说：Weren't it for the expense, I would go abroad now.

（来源：网络）