问个初级英语问题 if he had worked harder,he______

题目

问个初级英语问题 if he had worked harder,he______
A would succeed B had succeeded
C should succeed D would have succeeded 为什么选D 这是什么语法现象

答案

这是一个“虚拟语气”.
当if引导的条件状语从句与实际情况不相符时,要用虚拟语气,具体为：
与现在的情况不符：
从句中用 一般过去时/ be 动词用 were ; 主句中用 would / should / could / might + 动词原形
与过去的情况不符：
从句中用 had + done; 主句中用 would / should / could / might + have + done
与将来的情况不符：
从句中用 一般过去时/ be 动词用 were 或 were to + 动词原形; 或 should + 动词原形 ; 主句中用 would / should / could / might + 动词原形