embedded question
syntax134 sentences
A question clause embedded inside a larger sentence as a noun phrase — 'whether X,' 'what X,' 'where X' — that serves as an argument of a matrix verb like 知る, 分かる, 聞く, 説明する. Marked by か (or の+か for explanatory readings, かどうか for yes/no whether), enabling the question to function syntactically as a noun-like clause.