虚拟语气表示与将来事实相反的问题!从句谓语动词形式1.过去式（be用 were）2.were to +动词原型3.should+动词原型这三种有什么区别?可以通用吗?

虚拟语气在条件句中的用法列表如下：
相关时态 主句形式 从句形式 例句
与现在事实相反 Should\would\could\might+do（动词原形） 过去式（be动词各人称都用were） If I were you, I should \would make full use of my time to study.
与过去事实相反 Should\would\could\might+have done（动词过去分词） Had+done(过去分词) If you had come earlier, you would have met him.
与将来事实相反 Should\would\could\might+do（动词原形）
1. 过去式（be动词各人称都用were）
2. should+动词原形
3. were to +动词原形 If it should rain tomorrow, the crops would be saved.

可以