空气
kōngqì · HSK 2
air
💨 空 (empty) + 气 (gas/breath) = the empty gas all around us
空 means empty or sky, and 气 means gas, breath, or vapor. Together they name the invisible gas filling empty space — air. The same 气 shows up in 天气 (weather) and 氧气 (oxygen).
空 — cave radical 穴 + 工 (phonetic)
Originally a phono-semantic compound: 穴 (cave, hole) gives the meaning of emptiness or hollow space, while 工 supplies the sound. The earliest sense was 'hole' or 'cavity,' which extended to 'empty,' 'sky,' and 'in vain.' The reading kòng (4th tone) specifically means 'free time' or 'vacancy.'
气 — steam/vapor radical 气
Originally a pictograph of rising vapor or clouds drifting in the sky, depicting curling streams of air. The character came to mean breath, air, and by extension vital energy or 'qi.' The simplified form 气 keeps the original outline; the traditional 氣 added 米 (rice) to suggest steam rising from cooking grain.