The Mandarin question word for "wher” is zài nǎli. It is made up of three characters: 在 (zài) which means "located at," and the two characters nǎli - 哪裡 (trad) 哪里 (simp) mean wher?

Zài nǎli literally means, “wher is it located?”

Nǎli is sometimes used by itself, usually as a single-word question. Note the third tone is very important. If said with the fourth tone (nàli), the meaning is “there,” which is often said as an answer to “nǎli?”
Examples of Zai Nali

    Wǒde shū zài nǎli?
    我的書在哪裡? (trad)
    我的书在哪里? (simp)
    wher is my book?

    Wǒmen zài nǎli jiàn?
    我們在哪裡見? (trad)
    我们在哪里见? (simp)
    wher are we going to meet?