这是什么从句：Did you say that what he said was true

这是什么从句：Did you say that what he said was true
1.Did you say that what he said was true
那Did you say that he said was true 这句话对吗
如果对是什么从句?
2.请问所有从句都是用陈述语序吗?包括定语从句和状语从句?我知道名词性从句是.