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?
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?
答
would have done 表示本应该做什么而未做，有相关用发的还有should,如果添加not则表示本不该做而做了，应该重点记住这种特殊情况
答
would have + 动词的过去分词表示本应做某事
采纳把！
答
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!
答
虚拟语气，固定用法。