哪
which; where
nǎ
What does 哪 mean?
哪 (nǎ) is the Chinese question word 'which' — it picks one out of a known set. It pairs with a measure word and a noun: 哪个 (nǎ ge, 'which one'), 哪本书 (nǎ běn shū, 'which book'), 哪国人 (nǎ guó rén, 'which country's person → where are you from'). Combined with the suffix 儿 (-r) it becomes 哪儿 (nǎr) 'where,' which in Taiwan and southern China is usually written 哪里 (nǎlǐ). Two notes for English speakers: first, unlike English 'which,' Chinese 哪 always needs a measure word before the noun (you say 哪本书, not just 哪书); second, the tone changes in spoken speech — before a 第四声 it can soften toward něi (哪个 → něige), a colloquial variant you'll hear constantly in Beijing.
Character breakdown
which / where (mouth radical 口 + phonetic 那)
Memory hook: 哪 is 那 ('that') with a 口 (mouth) added — the mouth is asking 'which that?'
Example sentences
你是哪国人？
Nǐ shì nǎ guó rén?
Where are you from? (Which country's person are you?)
neutral
你住在哪儿？
Nǐ zhù zài nǎr?
Where do you live?
spoken
哪个是你的？
Nǎ ge shì nǐ de?
Which one is yours?
spoken
你喜欢哪本书？
Nǐ xǐhuan nǎ běn shū?
Which book do you like?
neutral
Common phrases with 哪
Synonyms
什么 means 'what' — asks open-endedly without a known set. 哪 means 'which' — asks you to pick from options. 你喜欢什么书? = 'what books do you like?' (open); 你喜欢哪本书? = 'which book do you like?' (from these).
Don't confuse 哪 with
那 (nà) means 'that' — a pointer to something specific. 哪 (nǎ) means 'which' — a question word. Same shape minus the 口 radical. 那个 = 'that one'; 哪个 = 'which one'. The tone is what your ear must catch in speech.
Both mean 'where.' 哪儿 dominates in northern mainland (especially Beijing); 哪里 dominates in southern China, Taiwan, and most written Chinese. They are fully interchangeable in meaning.