Had you come five minutes earlier,you __________ the train to Birmingham.But now you missed it.

问题描述:

Had you come five minutes earlier,you __________ the train to Birmingham.But now you missed it.
为什么空里填would have caught.而不是would catch或could catch或should catch?

have+过去分词 表示做过某事,这里不是说已经过去了吗?主要是说假如你来早5分钟,就应该赶上火车,这是说应该赶上!