Comparative form
规则变化
1. 单音节和部分双音节词，在原级上加er.est构成比较级和最高级
例如：older
2. 两个音节以上的，原级前加more/most构成比较级和最高级
例如：more popular
Most popular
不规则变化
例如：good-better-best
固定句型
1. 倍数
（1）倍数+As+形容词/副词(名词)+as
the subway train,approaching the station,can be twice as loud as the bus.
（2）倍数+名词+of (常用width、lenth、size等)
The sun is many times the size of the moon.
（3）倍数+比较级+than
Teddy’s head is twice times bigger than alex.
2. 同级比较
（1）As..as/the same..as 一样
He’s sleep time is the same long as pig.
他的睡眠时间和猪一样长。
（2）not more..than=not..any more than 都不，和...一样不,既不...也不
I could not do that any more than you.
你不能做这件事,我也不能做
This cellphone is not more intellgent than computer.
这部手机和电脑都不智能
3. 表示最高级
（1）否定+more
i can’t agree with you more
我在同意不过了
（2）More ..than anyone else 比其他任何都..
He practice more hard than anyone else
他比其他更加努力练习
（3）nothing so ..as 没有比..更
Nothing is so easy as for parents to raise their expectations of their children too high.
没有什么比父母对孩子期望过高更简单的了
魔鬼组..
4. No more than/no less than
We ran no more than three miles. 仅仅
She has no less than three books. 多达
She has not more than one car. 不超过
He has not less than seven car. 不少于
It’s no more a pig than a dog. 既不...也不
He is no less clever than you. 与..一样
She is not more diligent than he is. 不如
He is not less determined than you. 比..更
5. More than + 名词（动词）/数字/形容词
（1）more than + 名词（动词）表示——不仅，不只
They work very hard, more than earn their salaries
他们工作非常努力，而不仅仅是赚取薪水
（2）More than + 数字——多于，超过
More than two thousand scientists from eighty nations have taken part in the project.
来自八十个国家超过两千个科学家参与了这个项目
（3）More than + 形容词——完全有..，非常
I see you're more than capable of understanding it.
我知道完全有理解的能力。
6. nothing more than 只不过是
They expected nothing more than a newtype machine.
他们期望的只不过是一台新型的机器而已
7. Just so...as 正如..也
Just as you hate math, so I dislike chemistry.
正如你讨厌数学一样，我也不喜欢化学
8. not so much as/not so much...as
（1）not so much as 甚至..不/甚至..没
He had not so much as his fare home.
他甚至连回家的车费都没有。
（2）not so much...as 与其说是B不如说是A
They weren't so much islands as sandbars．
与其说那是些岛屿，还不如说都是些沙洲