虚拟语气用于非真实条件句时谓语动词的主要形式见下表：

　　以上结构中，主句谓语动词除了用would外，有时还可用might或could，第一人称还
　　可用should，但美国英语都用would。
　　如果条件句的谓语中含有were, had或should时，有时可省略if而用把were, had或
　　should放到主语之前的倒装句。现分别举例如下：

1. 与现在事实相反
　　If I knew French, I would read the book in the original.
　　If I were (Were I) in your position I would tell her the truth.

2. 与过去事实相反
　　If you had (Had you) come a few minutes earlier, you would have caught the train.

3. 与将来事实相反或表示推测
　　If he came tomorrow, I might have time to see him.
　　If it were (Were it) to rain next Sunday, the match would be postponed.
　　If we should (Should we) fail again, we wouldn't lose courage.