Question

这句是主语从句吗？

老师教案上说这个是主语从句， 我感觉是同位语从句 The fact that we were late to class really upset the teacher?

Answer 1

主语从句和同位语从句没太大区别，都是对旁边的名词起补充说明作用，阐述具体内容是什么

主要区别就是位置不一样，主语从句要么在句首，例如这句子就是，这句子是主语从句；
要么在句尾，句首用it代替做形式主语。

Answer 2

1、第一句话
That we were late to class
really upset the teacher.
that we were late to class 是主语从句。
2、第二句话
The fact that we were late to
class really upset the teacher.
that 引导的是同位语从句，和fact指的是同一内容。