久
long (time)
jiǔ
What does 久 mean?
久 (jiǔ) is an adjective/adverb meaning 'long (in time)' — describing how long something lasts or how long ago it was. It only refers to duration, never to physical length (for that, use 长 cháng). Common patterns: 很久 (hěn jiǔ) = a long time; 多久 (duō jiǔ) = how long?; 好久不见 (hǎojiǔ bú jiàn) = long time no see; 不久 (bù jiǔ) = not long / soon.
It typically appears after a verb to mark duration (我等了很久 = I waited a long time) or as part of a time-question (你来多久了？= How long have you been here?). English speakers often want to use 长 here because 'long time' translates 'long' as 长 — but for time, native speakers say 很久, not 很长 (though 很长时间 is fine). 久 is also a homophone of 九
Character breakdown
long (in time); for a long while
Memory hook: Same sound as 九 (nine) and 酒 (alcohol) — nine bottles of liquor takes a long time to finish.
Example sentences
好久不见！
Hǎojiǔ bú jiàn!
Long time no see!
spoken
你来中国多久了？
Nǐ lái Zhōngguó duō jiǔ le?
How long have you been in China?
spoken
我等了很久。
Wǒ děng le hěn jiǔ.
I waited a long time.
neutral
不久以后他就回来了。
Bù jiǔ yǐhòu tā jiù huílái le.
Not long after, he came back.
neutral
对不起，让你久等了。
Duìbuqǐ, ràng nǐ jiǔ děng le.
Sorry to have kept you waiting.
polite
Common phrases with 久
Synonyms
长时间 means 'a long period of time' and works as a noun phrase before a verb (长时间工作 = work for long periods). 久 is more compact and usually follows a verb (工作很久).
半天 literally 'half a day,' but spoken it means 'ages / a long while' (我等了半天 = I waited forever). 久 is neutral about duration; 半天 carries impatient feeling.