替代 (Substitution) 是一种避免重复和连接上下文的手段。对句子中相同的非关键性词语可用替代词来替代，从而达到避免重复的目的, 使文字更加精练，英语中的替代情况主要有以下三种：名词性替代、动词性替代和分句性替代。此外还有状语的替代。

一、名词性替代 

     用名词性替代词one(s), the same, the kind, the sort等所表示的替代现象叫做名词性替代。
1．名词性替代词
例如：
The child doesn’ t like this book. Show him a more interesting one. (one = book)
His novel is a bad one for children. (one = novel)
2．某些不定代词
在名词性替代中还可以用一些不定代词来替代。如all, both, some, any, enough, several, none, many, much, more, (the) most, (a) few, another, the other, others, either等。
例如：
I don't want any more food. I’ve had enough.
3. one 和 ones 是最常见的替代词
one的复数形式是ones. one 和ones作为替代词只能用以替代可数名词，不可用来替代不可数名词。
例如：
The grey horse is stronger than the black one.
The new design is much better than the old ones.
4．名词性物主代词mine，yours
名词性物主代词mine, yours等可用来代替my +名词，your +名词等，
例如：
 “Whose is that coat?” “It’s mine.”

二、动词性替代 

     用动词替代词do，do so等所表示的替代现象叫做动词性替代。
1．谓语的替代形式
do是谓语的替代形式，有时态和人称的变化。
例如：
Some people like a shower after they have played tennis. Peter does, for example.
John speaks German as fluently as Mary does.