'有用' (yǒu yòng) literally combines '有' (yǒu), meaning 'to have', and '用' (yòng), meaning 'use' or 'function'. Together, they form an adjective meaning 'useful'—something that serves a practical purpose or provides value. It describes objects, skills, information, or people who contribute effectively to a goal.

This word is commonly used in everyday contexts: describing tools, advice, knowledge, or personal abilities. Unlike some adjectives, '有用' typically follows the noun it modifies (e.g., '有用的信息') or appears after 是 (shì) in predicate position (e.g., '这个方法很有用'). It carries a neutral-to-positive connotation and is appropriate in both casual and formal speech, though it’s less common in highly literary or poetic registers.