be supposed todo sth怎么回答？

Question

如题所述

Answer 1

一、be supposed to do sth. 有多层含义

1. 必需做某事
* He is supposed to go to the store. 她必需去商店
2. 得到允许做某事:
* We are not supposed to smoke here. 我们在这儿不能抽烟
3. 坚信能够做某事
* You're supposed to be my friend. 我把你看成是我的朋友。

二、用于真实语气，后面跟不定式的一般式to do sth. 如上述例句。

三、用于虚拟语气，前面用过去式was/were supposed，后面跟不定式的完成式to have done sth. 如：

* He was supposed to have gone to the store. 她早就必需去商店。
* We were not supposed to have smoked here. 我们本不该在这儿抽烟
* You were supposed to have been my friend. 我早该把你看成是我的朋友。

四、“他两个小时前就该来了”是虚拟语气，因此应该用was/were supposed to have done sth. 即——

* He was supposed to have come two hours before. 或者——
* He was supposed to have been here two hours before.