第二条件句句型

第二条件句 (second conditional) 表示现在或将来不可能实现或实现的可能性很小的一种假设.
第二条件句中的谓语动词用一般过去时或should (were to)+动词原形,而主句中的谓语动词则用would / should / could / might+动词原形.在现代英语中,if非真实条件状语从句中的谓语动词如果是be,其过去形式一般用were.
例句：If I were you,I should not do that.
if 条件句中如有were,should,had,可以省去if,并使用倒装语序.
Were I a boy,I would join the army.