分不清楚什么时候用定语从句什么时候用名词性从句啦

Question

如题所述

Answer 1

定语从句就是修饰前面名词的句子，凡修饰名词的词、短语或句子就叫做定语。名词从句包括主语（宾语、表语、同位语）从句，名词从句顾名思义就是用作名词的句子，它在句子中可作主语、宾语、表语、和同位语。
This is the man whose sister is a nurse.
This is the house where he lived.
That he is ill is true.
I decide that we will start at 8.
That is what he said.
I know the fact that he once stayed there.