be supposed to do与was/were supposed to have done区别

问题描述:

be supposed to do与was/were supposed to have done
区别

be supposed to do 被期望做某事
was/were supposed to have done 被期望做完某事,却没有做。

be supposed to do 是指应该去做什么was/were supposed to have done 是指一种虚拟,是指本来应该做的,但是事实上并没有发生例如you were supposed to have finished the work,but i haven't seen it now...