The word "哪些" is formed through the direct combination of two distinct characters, each contributing its core meaning to create a new, composite idea. The character "哪" (nǎ) functions as an interrogative element meaning "which", while "些" (xiē) acts as a quantitative element indicating an indefinite plural amount, meaning "some". Their fusion is not arbitrary but follows a common pattern in Chinese where a question word is paired with a measure or pluralizer; in this case, "哪" specifies the interrogative nature and "些" specifies that the inquiry is about a plurality, thereby yielding the combined meaning of "which ones" or "which (plural items)".