更换
gēnghuàn · HSK 5
replace
🔄 更 = change/alter + 换 = exchange/swap; doubled-up 'replace'
更 (gēng) means to change or renew; 换 (huàn) means to exchange or swap. Stacked together, the two near-synonyms reinforce the sense of swapping one thing out for another.
更 — 丙 (bǐng) phonetic + 攴/攵 (action/strike)
Originally an oracle-bone graph showing a hand striking a watch-drum to mark night watches, hence 'to change shifts.' From this came the meanings 'to change' and 'to replace' (gēng). The reading gèng later developed the sense 'further, even more,' as in 'one watch further on.'
换 — hand radical 扌 + 奂 huàn (phonetic)
换 is a semantic-phonetic compound. The hand radical 扌 signals an action done with the hands, while 奂 supplies the sound huàn. The original sense of exchanging or swapping things by hand extended naturally to broader meanings like 'change' or 'replace'.