关于It is +adj +that这个句型的问题

问题描述:

关于It is +adj +that这个句型的问题
为什么有It is a pity that
It is 后面不是应该加形容词吗?
a pity是名词吧

It's + adj/n +to do/that从句
It's no good to watch too much TV.(名词)
It's not good to watch too much TV.(形容词)