The compound word **前夜 (qiányè)** is formed through the combination of two meaningful characters: **前 (qián)**, meaning "before" or "in front," and **夜 (yè)**, meaning "night." It follows a standard **modifier-head** structure in Chinese morphology, where "前" modifies "夜" to create the literal meaning of "the night before." This literal sense is then extended **metaphorically** to signify the immediate period or eve leading up to any significant event (e.g., 战争前夜, "the eve of war"). Thus, its formation is both semantically transparent and culturally illustrative, evolving from a concrete time reference to an abstract figurative term.