The word "打球" is formed by combining two characters: "打", which conveys the action of hitting or striking, and "球", which means ball. Together, they create a compound where the action directly relates to the object, effectively meaning "to hit a ball" and, by extension, to play ball sports such as basketball or tennis. This structure intuitively merges a verb and a noun to depict a common activity, reflecting how Chinese often builds words through descriptive pairings that immediately communicate their purpose.