A.“比较级+ and +比较级”或“more and more +原级”表示“越来越……”.
It is getting cooler and cooler.
天气越来越凉爽.
The wind became more and more heavily.
风变得越来越大.
B.“the +比较级……,the+比较级”,表示“越……越……”.
The more money you make,the more you spend.
钱你赚得越多,花得越多.
The sooner,the better.越快越好.
C.表示倍数的比较级用法：
a.A is …times the size /height/length/width of B.
The new building is three times the height of the old one.
这座新楼比那座旧楼高三倍.(新楼是旧楼的四倍高)
b.A is …times as big /high/long/wide/large as B.
Asia is four times as large as Europe.
亚洲是欧洲的四倍大.(亚洲比欧洲大三倍)
c.A is …times larger /higher/longer/wider than B.
Our school is twice bigger than yours.
我们学校比你们学校大两倍.
大多数形容词（性质形容词）和副词有比较级和最高级的变化,即原级、比较级和最高级,用来表示事物的等级差别.原级即形容词的原形,比较级和最高级有规则变化和不规则变化两种.
1) 规则变化
单音节词和少数双音节词,加词尾-er,-est来构成比较级和最高级.
构成法 原级 比较级 最高级
一般单音节词 tall(高的) taller tallest
末尾加-er,-est great(巨大的) greater greatest
以不发音的e结尾和以- le结尾的双音节词只加-r,-st
nice(好的) nicer nicest ,able（有能力的) abler ablest
以一个辅音字母结尾的闭音节单音节词,双写结尾的辅音字母,再加-er,-est
big(大的) bigger biggest
hot热的) hotter hottest
"以辅音字母+y"结尾的双音节词改y为i,再加
-er,-est easy(容易的)
easier easiest ,busy(忙的) busier busiest
少数以-er,-ow结尾的双音节词末尾加-er,-est
clever(聪明的) cleverer cleverest
narrow(窄的) narrower narrowest
其他双音节词和 important(重要的)
多音节词,在前 more important
面加more,most most important
来构成比较级和 easily(容易地)
最高级.more easily
most easily
2) 不规则变化
原级 比较级 最高级
good(好的)/ better best
well(健康的)
bad (坏的)/ worse worst
ill(有病的)
old (老的) older/elder oldest/eldest
much/many(多的) more most
little(少的) less least
far (远的) farther/further farthest/furthest
比较级形容词或副词 + than
You are taller than I am./ You are taller than me.
The lights in your room are as bright as those in mine.
注意：
1）要避免重复使用比较级.
(错) He is more cleverer than his brother.
(对) He is more clever than his brother.
(对) He is cleverer than his brother.
2）要避免将主语含在比较对象中.
(错) China is larger that any country in Asia.
(对) China is larger than any other country in Asia.
3）要注意对应句型,遵循前后一致的原则.
The population of Shanghai is larger than that of Beijing.
It is easier to make a plan than to carry it out.
4）要注意冠词的使用,后有名词的时候,前面才有可能有名词.
比较：Which is larger,Canada or Australia?
Which is the larger country,Canada or Australia?
She is taller than her two sisters.
She is the taller of the two sisters.
可修饰比较级的词
1）a bit,a little,rather,much,far,by far,many,a lot,lots,a great deal,any,still,even等
2）还可以用表示倍数的词或度量名词作修饰语.
3）以上词(除by far)外,必须置于比较级形容词或副词的前面.