(2)虚拟条件句
表示所提出的假设实现的可能性极小与事实相反, 谓语动词用虚拟语气. 虚拟语气也可以表示愿望,请求及建议等.
If it had rained yesterday, we would have stayed at home.
如果昨天下雨的话,我们就会留在家里。