Literal meaning

review (温) — old (故) — know (知) — new (新)

Origin

Straight from the Analects (《论语·为政》): 温故而知新，可以为师矣 — "One who can revisit the old and find new meaning in it is fit to be a teacher." Confucius's point isn't just "review your notes before a test." It's a claim about learning itself — that fresh understanding is mostly produced by going back over what you thought you already knew with a new eye. The phrase has stayed in active use for 2,500 years because that observation keeps being true.

Examples

Usage & nuances

Works in spoken and written Chinese; very common in educational contexts (teachers, parents, study apps). Often used reflexively about one's own re-reading — "温故知新的感觉" — rather than as advice to someone else.