What引导的宾语从句只能是特殊疑问句吗?

题目

What引导的宾语从句只能是特殊疑问句吗?
some children want to challenge themselves by learning a language different from what their parents speak at home.这句中的what their parents speak at home提出来也没办法还原成特殊疑问句啊,还原回去翻不通啊.这个怎么回事啊?

答案

这里的what 不是作为疑问词来用,它在句中做了句子成分的做speak 的宾语,这是一个宾语从句,还原了应该是their parents speak what at home@!意为他么父母在家所说的