"[K??]" question is a sentence pattern commonly used to express doubt in Chaohu dialect. "[K??]" questions in Chaohu dialect can be divided into three categories: "[K??]VP", "[K??] 是 NP" and "[K??] 是 VP". "[K??]" questions can also express different tenses by co-occurrence with different tense and aspect auxiliary words. As for the nature of "[K??]" questions, we conclude that, "[K??]VP" sentence pattern in Chaohu dialect has a double corresponding relationship with neutral repeated questions and neutral yes or no questions in Putonghua. "[K??]是NP" has a corresponding relationship with neutral repeated questions in Putonghua; "[K??]是 VP" has a double corresponding relationship with tendency repeated questions and "是不是"(yes or no)questions in Putonghua.