长

长 (cháng) is the everyday adjective for 'long' — used for length in space and duration in time. Spatial: 长头发 ('long hair'), 长江 ('the Long River' = Yangtze), 这条路很长 ('this road is long'). Temporal: 时间很长 ('a long time'), 长假 ('a long holiday'). The character has a second important reading — zhǎng (third tone) — which means 'to grow' (长大 'to grow up') and 'chief / oldest' (校长 'school principal,' 长子 'eldest son'). Same character, two completely separate words; readers must guess from context which one is meant. As cháng, 长 takes the standard adjective slot and pairs with 很 ('very'), 太…了 ('too…'), and degree adverbs: 太长了 ('too long'). The opposite is 短 (duǎn). When measuring, Chinese reverses the English word order: ask 多长 ('how long?') and answer with the number + 长 — 三米长 ('three meters long').

Note: Two readings of the same character — second-tone cháng ('long') is the HSK 2 word; third-tone zhǎng ('to grow / chief') is a separate vocabulary item learners should not confuse.

Memory hook: Picture a single long hair stretching down — that's the original pictograph behind 长.