调查
diàochá · HSK 3
investigate
🔍 调 (adjust/probe) + 查 (check/examine) = probe + check → investigate
调 carries the sense of tuning or probing, and 查 means to check or inspect. Together they describe a methodical look into something — an investigation or survey.
调 — speech radical 讠(言) + 周 zhōu (phonetic)
调 is a semantic-phonetic compound. The 讠(言) radical signals 'speech' or 'words,' while 周 supplies the sound. Originally meaning to harmonize or coordinate through words, it later extended to 'tune,' 'adjust,' and 'melody' (read diào), and 'mix evenly' or 'mediate' (read tiáo).
查 — wood 木 + sun-on-tree 旦-like 且
Originally a variant form related to 楂 (a type of raft or wooden float), combining 木 (tree/wood) with 且 as phonetic. Over time it shifted to mean 'to inspect' or 'investigate,' likely through the idea of examining wood or tallies. The reading chá for 'check' became dominant in modern usage.