陳思's 心英文法---英文心法

不定代名詞(Indefinite Pronoun)

不定代名詞：多由不定形容詞(Indefinite Adjective)借用而來，故此章節順便將不定形容詞用法一併解說。

one：本是數詞(Numeral Adj.)，轉作不定代名詞可以表示凡是人，任何人。

努力的人會成功
  One who works hard will succeed.

= Anyone that works hard will succeed.

= Everyone that works hard will succeed.

= People who work hard will succeed.

= Those who work hard will succeed.

one亦可代表已經提過的不特定之可數名詞，多數時須加“s”。
 
I have three dogs, a black one and two white ones.
Your cat is cute; I would like to keep one.(我想養一隻…與前述不同一物)
Your cat is cute; I would like to keep it. (我想養牠…與前述同一物)

one不可代替不可數名詞

 Which one do you like better, white wine or red wine?(誤)
 Which do you like better, white wine or red wine?(正)

I like red wine better, thank you. (正)
I like red better, thank you. (正)
I like red one better, thank you. (誤)

one不可放在所有格之後
My car is smaller than yours. (正)
My car is smaller than your one. (誤)

one可放在定冠詞the之後，不可直接放在不定冠詞a、an之後
This book is the one that I am looking for. (正)
This book is one of the books that I am looking for. (正)
This book is a one that I am looking for. (誤)

one之前可放形容詞以修飾之，Adj. + one可放在不定冠詞a、an之後
A: This sweater is too small to me.
B: No problem. I can get you a bigger one.

This straw is too short; I need a longer one.(正)
This straw is too short; I need one longer. (正)
This straw is too short; I need a one longer. (口語可，考題勿用)