one
one 在英文的用法上並不簡單。它有三個用法：
(a) 做量詞，解作「壹」。例如：
I want one book, not two!
(b) 做代名詞，依上下文來定意義。例如：
I don't like this book; I want that one [book].
其複數型是：
I don't like these books; I want those ones [books].
(c) 做名詞，解作「每個人」。例如：
One has to learn as long as one lives.
One shall work not only for oneself but also for others.
厲害！由於用法多，所以很容易攪亂。希望以後大家不要瞎來了。
by Thomas Shum