one與ones用來代替上文的一個或多個人或事物:
如: Which jacket would you like, this one or that one?
你要哪件夾克, 這件還是那件?
I don’t like the green ones.
我不喜歡綠色的那些。
前面可以加冠詞
-- Give me a pen, please.
--Which pen? This one?
--No, not that one. The one on the shelf.
2. 前面可以放形容詞
Among all the boys, Sam is the tallest one.
I want the long one.
3. 前面可以放指示代詞,也可以放 which
--Give me some cups, please.
-- Which ones? These ones?
--No, not those ones. The empty ones.