Question

That is exactly what I want to say。

句子的意思明白，但是句子结构（语法）不懂，请分析一下这个句子，谢谢

Answer 1

That 主语
is系动词

exactly
what I want to say表语从句

what引导词
作表语从句中
I want to say 的宾语
。

Answer 2

这是一个表语从句

That is exactly what I want to say。

追答

That 主句主语 is 系动词 exactly 副词做状语 what 引导词做从句宾语 I 从句主语 want to say从句谓语