题目内容：

be supposed to 和should have done
WAS SUPPOSED TO表示应该做某事而未做
WAS NOT SUPPOSED TO表示不应做某事却做了
SHOULD HAVE DONE 表示因该做某事而未做
SHOULD NOT HAVE DONE表示不应做某事却做了
WAS SUPPOSED TO表示应该做某事而未做
这四个有什么关系的?比如两两相等用法?

优质解答

be supposed to=shouldbe not supposed to= shouldn't完全相等 就表示应该做什么 前者有不同时态 后者没有时态区分was supposed to 过去应该做某事 事实就是没做 强调过去的那个时候应该发生 时间should have done ...