hard-working、hard working、working hard 区别.hard-working是名词吗?

问题描述:

hard-working、hard working、working hard 区别.
hard-working是名词吗?

hard-working是adj.
不是名词
hard working就是hard-working
working hard
例:He is working hard for the finals. 他正在努力准备期末考试.