be supposed to 和should have done

e supposed to=should
be 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 表示本应该做某事而没做 强调原本应该做的 事情
如,he was supposed to come yesterday 他昨天就该来
You should really have done it yourself.你应该自己做这件事