This paper discusses the origin of the interrogative pronoun"What+X"in Wuzhou Wu dialects,which stems from the grammaticalization of the locative word"da(埭)",forming a combination known as"shida(是埭)"when starting with affricate initials.In contrast,the interrogative pronoun"Who+X",beginning with lateral initials,doesn't originate from"na(哪)"but rather from"da(埭)".The transformation from d-to l-in this context is influenced by the pulling of the"na(哪)".Additionally,the paper explores the hierarchy system of interrogative pronouns in Yiwu dialect.It suggests that the word"da(埭)"has undergone two expansions,resulting in a two-layer interrogative pronoun system.The first expansion gives rise to pronouns related to individuals and locations,which extends to include other interrogative pronouns,leading to the second expansion.