英语语法题（虚拟语气）,求详解

题目

英语语法题（虚拟语气）,求详解
1.Tom might have come to Professer Smith's lecture but he got up rather late.(为什么填but he got up rather late,可以用if he had gotten up early么）

答案

当If 表虚拟语气时候,表示与过去事实相反：If ...had done ...,...would(might,could) have done...从句谓语动词用had+done,主句用should/would/could/might+have+done结构.所以这个句子如果用if从句 的话,应该是Tom...