只要 (zhǐ yào) is a conjunction meaning 'as long as' or 'provided that'. It introduces a sufficient condition — the clause following 只要 expresses the minimum requirement needed for the main clause to hold true. Literally, 只 means 'only' and 要 means 'must/want', so together they convey the idea of 'only needing this one thing' — hence 'as long as'. It’s commonly used in both spoken and written Chinese to express conditional logic, often with positive or encouraging outcomes.

This expression typically appears at the beginning of a subordinate clause, followed by a comma or directly linked to the main clause. It implies optimism or reassurance: the condition is easy to meet, and the result is almost guaranteed if it is. 只要 is neutral in register and widely appropriate across contexts — from casual conversation ('只要按时交作业，就能及格') to formal writing ('只要坚持改革，经济就会持续增长'). It contrasts with 更多 (gèng duō) or 除非 (chú fēi), which introduce stronger or negative conditions.