would have done和 should have done的区别是什么?意思分别是什么

would/should + have + 过去分词 这是虚拟语气的一种用法.would have done ：表示对过去事情的假设,意思是“本来会做”.比如：I would have told you all about the boy's story,but you didn't ask me.我本来会告诉...