what his mother said didn't change Martin's mind.这是个主语从句 为什么不是his mother said what

问题描述:

what his mother said didn't change Martin's mind.这是个主语从句 为什么不是his mother said what
如题 为什么what要在句首

what his mother said 是一个主语从句,相当于一个主语,his mother said what是典型的汉语是表达,显然不对