The weather here is not as hot as that in the south.
 4.A比B更…
 The earth is bigger than the moon.
 5.比较级前可以用much,even,still,far,a lot,a little,a bit,any等修饰。
 Your room is much bigger than mine.
 I’m a little shorter than her.
 6.用比较级可以表示最高级含义：
 John is stronger than any other boy in his class.=John is stronger than any of the other boys.
 两者不属于同一范畴，不能用other.
 Chongqing is bigger than any city in Sichuang.
 7.“比较级+and+比较级”   表示“越来越…”
 China is becoming more and more beautiful.
 Days are getting longer and longer.
 8.用the+比较级，the+比较级  表示”越…就越…”.
 The busier he is, the happier he feels.
 9. Which/Who+is+比较级     A或B？
 A和B哪一个/谁更…?
 Which is better,this one or that one?

 最高级用法：
 表示三者或三者以上的人或物的比较，一个在某方面超过其他两个或多个时，用最高级，结构是
 主语+系动词+the+形容词最高级+of/in短语。
 This story is the most interesting of the three.
 1. one of the+形容词最高级+名词复数
 它的意思是最…之一。
 English is one of the most important languages in the world.
 2. which/who…+is+形容词最高级
 “…最...”
 Which is the heaviest,the horse,the sheep or the elephant?
3.最高级前可以用序数词
 The Yellow River is the second longest river in China.

形容词的比较级和最高级的变化规则：

构成	原级	比较级	最高级
一般加er，est	tall	taller	tallest
以字母e结尾只 加 r,st	large	larger	largest
以一个辅音字母结尾的 重读闭音节，双写这一辅 音字母后再加er,est	red	redder	reddest
	hot	hotter	hottest
	thin	thinner	thinnest
以辅音字母+y结尾的词， 将y变为i再加er,est	easy	easier	easiest
	happy	happier	happiest
	ugly	uglier	ugliest
	early	earlier	earliest
其他双音节词和多 音节词，在词前 加more或most	interesting	more interesting	most interesting