The word "疑问" is formed through the logical combination of two independent characters, each contributing a core meaning to create a new, composite concept. The first character, "疑" (yí), carries the intrinsic idea of "doubt" or "uncertainty". It is then directly paired with the second character, "问" (wèn), which embodies the fundamental notion of "to ask" or "a question". Thus, the formation is a conceptual synthesis: "doubt" + "question" seamlessly merges to express the integrated idea of a "doubtful question", or simply, a "query" or "doubt".