证书
zhèng shū · HSK 5
certificate
📜 证书 = zhèng (proof) + shū (document)
证 means proof or evidence; 书 means book or document. Together they form a proof-document — a certificate. The 书 component also appears in 书本 (book) and 书写 (to write).
证 — speech radical 讠 + 正 (correct/upright)
证 is a semantic-phonetic compound. The speech radical 讠 (言) signals it relates to words or testimony, while 正 (zhèng, 'upright/correct') gives the sound and hints at 'verifying truth.' Originally written 證, it meant to testify or prove; today it means evidence, certificate, or to prove.
书 — hand 又 holding brush over 曰 (say/speak)
Originally a pictograph of a hand gripping a writing brush above a mouth or vessel, depicting the act of writing speech down. The traditional form 書 shows 聿 (brush) over 曰 (to say). Simplified 书 preserves the brush-in-hand shape, and the meaning extended from 'to write' to 'writing' and then 'book'.