一道单选must have been 和would have been的区别?
问题描述：
一道单选must have been 和would have been的区别?
Jack described his father, who _______a brave boy many years ago, as a strong–willed man
A. would be B. would have been C. must be D. must have been
我不能理解为什么不能用would表示过去,他父亲过去是一个勇敢地男孩不行吗?
老师说would be可以说是过去的某个事。比如说：I would be a clever boy.之类的。
答
would have been 表示过去可能会发生而实际没有发生的事,例如：
If it hadn't rained,we would have got there on time.(实际上是天下了雨,我们当时没有按时到.）
must have been 则表示对过去非常肯定的推测,例如：
He must have been happy at that time.(那时他一定很幸福.）