虚拟语气should have

虚拟语气should have 虚拟语气 should have done 与 could have done 虚拟语气中的SHOULD 英语：should have done是否用于虚拟语气? 虚拟语气 would 或should? 虚拟语气什么时候省略should 英语虚拟语气主语+would/should/could.动词原形 / have+pp 中would/should/cou ought to have done和should have done都是虚拟语气,只是前者 虚拟语气里对过去的虚拟即should\could\might+动词过去完成时和另一种虚拟语气情态动词+HAVE DONE 虚拟语气could/should/would/might +have done 用法的差别? 英语 虚拟语气习题The first thing you should have learned at college 虚拟语气中的would/conld/should do/have done 与 did/had done有何区别