as什么时候做介词，什么时候是连词，怎么区分？

Question

如题所述

Answer 1

as 作为连词，意思是（用于比较）与…一样。 还有当。。。时候

He can run as fast as I can.
他能跑得和我一样快。
She works in the same building as my sister.
她和我的妹妹在同一大楼上班。
This is the same as it was before.
这个与以前一样。
而作为介词，意思是：
正如，照
as you know
正如你知道的
就…而言
He's quite good, as boys go.
就男孩儿而言，他相当不错了。

像…
（指处于某种状态、 性质、情况、工作等之中）
He works as a driver.
他以开汽车为业。
The kitten uses that box as a bed.
小猫把那盒子当作床。