比较结构是常用结构，正确地使用这一结构可以使文章句式变化，提高写作水平。下面是比较结构一些常用表达方法。
1）同级比较
In 1998 we produced as many cars as we did in the previous five years.
We have accomplished as much in the past three years as would have taken ten years in the past.

2）比较级
Children now enjoy better medical treatment than before.

3）最高级
This is the most interesting book I've ever read.

4）the more…，the more…结构
The harder you work, the greater progress you will make.

5）选择比较
I prefer staying at home to going out.
He prefers to work alone.
They prefer to work rather than (to) sit idly.

6)对比
Motion is absolute while stagnation is relative.
He is tired out, whereas she is full of vigour.
注意：while 和whereas均可用于连接两个意义对立分句，相当于汉语“而”字。