which
國小小三下/wɪtʃ/
pron.哪一個（範圍有限時）
used to ask about one thing from a limited group
什麼時候用
選項有限用 which，範圍不限用 what。
常見錯誤
- Which is your favorite color?（有色卡可選）／What is your favorite color?（不限）
例句
Which one do you want?
你要哪一個？
the book which I bought
我買的那本書