使用
しよう · shiyou · JLPT N3 · noun
use
🔧 使用 = 使 (use, employ) + 用 (use, purpose): use-use, formal usage
Both kanji mean use: 使 is the one in 使う (つかう, to use) and 用 appears in 用事 (business, errand). Doubling them makes the formal noun, and する turns it into a verb: 使用する. Sound hook: shiyou is close to she-yo, as in she uses a yo-yo.
使 — person radical 亻 + official 吏
Originally a phono-semantic compound: 亻 (person) gives the meaning and 吏 (official, also a phonetic clue) suggests the sound. The early sense was 'to send a person on a mission,' from which came 'envoy/messenger' and the broader meanings 'to use' and 'to cause/make.'
用 — pictograph of a bucket or wooden pail
用 originally depicted a bucket or container, possibly a sacrificial vessel made of wood. Over time it was borrowed to mean 'to use' or 'employ,' losing its concrete object sense. The modern meaning 'use' has been standard since early classical Chinese.