The word 唱歌 is formed by combining two independent characters, each with its own meaning, into a single conceptual unit. The first character, 唱 (chàng), means "to sing" as a vocal action. The second character, 歌 (gē), means "song" as a noun or artistic form. When placed together, they create a compound word where the action is directed toward its natural object, conceptually merging to represent the complete activity of singing a song.