How do I say 'where'?
The standard universal 'where' — understood everywhere, slightly more formal or southern than 哪儿.
哪里
Where.
Where.
Where.
WHEN IT FITS
The 哪里 vs 哪儿 split is one of the most noticeable north-south differences in spoken Chinese. 哪儿 (with the 儿化 -r suffix) is northern speech, especially Beijing. 哪里 is universal and standard, felt as slightly more formal or southern. Both are correct everywhere; choosing one signals your linguistic background.
The cultural bonus: 哪里哪里 is the traditional humble response to a compliment. When someone says 你的中文说得真好 (“your Chinese is really good”), answering 哪里哪里 means “not at all, you’re too kind.” It deflects praise by questioning where it could possibly be coming from. Younger urban speakers increasingly use 没有啦 or just 谢谢 instead, but 哪里哪里 remains instantly understood and warmly received — it marks you as culturally literate, not just linguistically competent.
HOW PEOPLE ACTUALLY SAY IT
卫生间在哪里？
Where is the bathroom?
Asking for a location你是哪里人？
Where are you from?
Asking about hometownCHOOSE BY SITUATION
哪儿
Where (colloquial, northern).
Everyday speech, especially in Beijing and northern China — 你在哪儿？什么地方
What place / where.
Asking more broadly — 这是什么地方？= What is this place?