Question

原来是特殊疑问句做宾语从句的语法

原来如此

Answer 1

可以这么说。特殊问句中的疑问词如how,where,why,是副词，但在名词性从句中，是连接词。
如：
How is also a conjunction. how也是连词。
I don't want to know how he died...
我不想知道他是怎么死的。
why CONJ-SUBORD 连词
(用于从句句首)为什么 You use why at the beginning of a clause in which you talk about the reasons for something
I can't understand why they don't want us.
我不明白为什么他们不要我们。