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
未尾加-er,-est great(巨大的) greater greatest
以不发音的e结尾 nice(好的) nicer nicest
的单音词和少数 large(大的) larger largest
以- le结尾的双 able（有能力的) abler ablest
音节词只加-r,-st
以一个辅音字母 big(大的) bigger biggest
结尾的闭音节单 hot热的) hotter hottest
音节词,双写结
尾的辅音字母,
再加-er,-est
"以辅音字母+y" easy(容易的) easier easiest
结尾的双音节词,busy(忙的) busier busiest
改y为i,再加
-er,-est
少数以-er,-ow clever(聪明的) cleverer cleverest
结尾的双音节词 narrow(窄的) narrower narrowest
未尾加-er,-est
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
as + 形容词或副词原级 + as
1）在否定句或疑问句中可用so… as.
He cannot run so/as fast as you.
2）当as… as 中间有名词时采用以下格式.
as +形容词+ a +单数名词
as + many/much +名词
This is as good an example as the other is.
I can carry as much paper as you can..
3）用表示倍数的词或其他程度副词做修饰语时,放在as的前面.
This room is twice as big as that one.
Your room is the same size as mine.
4) 倍数+ as + adj. + as 倍数+ then + of
This bridge is three times as long as that one.
This bridge is three times the length of that one.
Your room is twice as large as mine.
Your room is twice the size of mine.
比较级形容词或副词 + than
You are taller than I.
They 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 clever 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 countries 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 large, 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.
典型例题:
1） ---- Are you feeling ____?
---- Yes,I'm fine now.
A. any well B. any better C. quite good
D. quite better
答案：B. any 可修饰比较级,quite修饰原级,well的比较级为better.
2）The experiment was____ easier than we had expected.
A. more B. much more C. much
D. more much
答案：C. much可修饰比较级,因此B,C都说得通,但easier本身已是比较级,不需more,因此C为正确答案.
3）If there were no examinations, we should have ___ at school.
A. the happiest time B. a more happier time
C. much happiest time D. a much happier time
答案：D.
many,old 和 far
1) 如果后接名词时, much more +不可数名词
many more +可数名词复数
2) old 有两种比较级和最高级形式: older/oldest 和elder/eldest. elder,eldest 只用于兄弟姐妹的长幼关系.
My elder brother is an engineer.
Mary is the eldest of the three sisters.
3) far 有两种比较级,farther,further. 在英语中两者都可指距离.
在美语中,father 表示距离,further表示进一步.
I have nothing further to say.
the + 最高级 + 比较范围
1) The Sahara is the biggest desert in the world.
形容词最高级前通常必须用定冠词 the,副词最高级前可不用.
形容词most前面没有the,不表示最高级的含义,只表示"非常".
It is a most important problem.
=It is a very important problem.
注意： 使用最高级要注意将主语包括在比较范围内.
(错) Tom is the tallest of his three brothers.
(对) Tom is the tallest of the three brothers.
2) 下列词可修饰最高级,by far, far, much, mostly, almost
This hat is nearly / almost the biggest.
注意：
a. very可修饰最高级,但位置与much不同.
This is the very best.
This is much the best.
b. 序数词通常只修饰最高级.
Africa is the second largest continent.
3) 句型转换：
Mike is the most intelligent in his class.
Mike is more intelligent than any other students in his class.
4) "否定词语+比较级","否定词语+ so… as"结构表示最高级含义.
Nothing is so easy as this.
=Nothing is easier than this.
=This is the easiest thing.
和more有关的词组
1) the more… the more… 越……就越……
The harder you work,the greater progress you'll make.
2) more B than A 与其说A不如说B
less A than B
He is more lazy than slow at his work.
= He is less slow than lazy at his work.
3) no more… than… 与……一样……,不比……多
The officials could see no more than the Emperor.
no less… than… 与……一样……
He is no less diligent than you.
4) more than 不只是,非常
She is more than kind to us all.
典型例题
1）The weather in China is different from____.
A. in America B. one in America C. America
D. that in America
答案：D. 本题意为"中国的天气比美国热."比较的是天气而不是国家,C不能选.A没有名词,后句成分不全,排除.B和D中,B中的one常用来代替可数名词,而that可车以代替不可数或抽象名词,所以选D.
2）After the new technique was introduced,the factory produced ___ tractors in 1988 as the year before.
A. as twice many B. as many twice C. twice as many D. twice many as
答案C. 此句意为"这个厂1988能生产的拖拉机是往年的两倍". 表示倍数用"倍数+ as + 形容词原形+ as +比较对象"的句型.所以此句答案为C.
This ruler is three times as long as that one.
