形容词最高级用于三者或三者以上的人或事物之间的比较，其中一个“最……”的情况，其形式的构成在教材中我们已经见过了，但真正掌握它的用法，还需破解几项常见“密码”。
【1号密码】形容词最高级前必须加定冠词the，但如果最高级前有物主代词、指示代词、名词所有格等修饰时，则不用定冠词。
如：My oldest daughter is 16 years old. 我最大的女儿16岁。
【2号密码】形容词最高级常与由介词in或of引导的表示范围的短语连用。
若介词后的名词或代词与句中的主语是同一事物时，则用of短语；当只说明是在某一空间、时间范围内的比较时，则用in短语。
如：This apple is the biggest of all. 在所有的苹果中，这个苹果最大。
He is the youngest in his class. 他在他班里年龄最小。
【3号密码】形容词最高级前可用序数词限定，共同修饰后面的名词，其结构为：“the+序数词+形容词最高级+名词”。
如：Hainan is the second largest island in China. 海南是中国的第二大岛。
【4号密码】形容词最高级的意义还可以用比较级形式表达。
常见的有：(1)形容词比较级+than any other+单数名词。
如：This is more difficult than any other book here.(=This is the most difficult book of all.)这些书当中这本最难。
(2)形容词比较级+than the other+复数名词。
如：Asia is bigger than the other continents on the earth.亚洲是地球上最大的洲。
【5号密码】形容词最高级前若有不定冠词a，这时，它不表示比较，而表示“非常”的意思。
如：Spring is a best season. 春天是一个非常好的季节。
形容词比较级练习1. Bob never does his homework_____ Mary. He makes lots of mistakes.A. so careful asB. as carefully asC. carefully asD. as careful as2. I feel __ better than yesterday. A. more B. very C. the D. far3. China has a larger population than __ in the world.A. all the countriesB. every countryC. any countryD. any other country4.This book is __ on the subject .A. the much bestB. much the bestC. very much bestD. very the best5. What animal do you like ___? I like all kinds of animals.A. betterB. bestC. veryD. well6.Hainan is a very large island. It’s the second__ island in China.rgeB. largerC. largestD. most largually Xiao Li spends __ time doing homework than XiaoChen does.A.little B less C. few D. fewer二.用所给词的恰当形式填空。
1.Which is _______ (big) ,the sun,the moon or the earth?2.Which is ______ (beautiful),the black coat or the blue one?3.this mooncake is ____ (cheap) of all.4.He is _______ (strong) in the class.5.English is ____ (widely)spoken in the world【变化】1. 规则形式1) 一般在单音节的形容词和少数双音节的形容词的词尾加er，est构成其比较级和最高级. great—greater—greatest2) 词尾已经有e，则只加r，st。
nice—nicer—nicest3) 以辅音字母加y为结尾的形容词，将y改为i，再加er，est，构成其比较级和最高级，happy—happier—happiest busy — busier — busiest4) 重读闭音节结尾，且词尾只有一个辅音字母，要将这个辅音字母双写后，再加er，est构成其比较级和最高级。
big — bigger — biggest5) 其它双音节和多音节的形容词，都是在其前面加more，most构成其比较级和最高级，useful→more useful→most useful◎练习1原级比较级最高级new _______ ________ short _______ ________great _________ ________ fast _________ ________◎练习2原级比较级最高级fine ________ _________ nice ________ _________◎练习3+y 去y+iest原级比较级最高级happy _________ _________ early _________ _________◎练习4重复字尾字+est原级比较级最高级big _________ _________ hot _________ _________sad _________ _________ fat _________ _________◎练习5原级比较级最高级difficult _________________________ _______________________careful _________________________ _______________________useful _________________________ _______________________2表示倍数的比较级有如下几种句型：A) A is three(four，ete) times the size(height，length，width，etc) of B．例如；The new building is four times the size( the height) of the old one．这座新楼是那座旧楼的四倍(四倍高)。
(这座新楼比那座旧楼大三倍[高三倍])．B) A is three(four，etc) times as big(high，long，wide，etc．) as B．例如：Asia is four times as large as Europe，亚洲是欧洲的四倍大．(亚洲是欧洲的三倍大．)C) A is three(four，etc．) times bigger ( higher，longer，wider，etc．) than B．例如：Your school is three times bigger than ours，你们的学校比我们的学校大三倍．(你们的学校是我们学校的四倍大．)用times表示倍数，一般只限于表示包括基数在内三倍或三倍以上的数．表示两倍可以用twice或double形容词与副词比较级和最高级的重点句型归纳⑴ A>B或A<B（…比较级+than…）This room is smaller than that one. This story is more interesting than that one.⑵ A=B（…as+原级+as…）This cake is as big as that one. Swimming is as exciting as climbing.⑶A≠ B not as/so+原级+as… 与……不一样Jim is not as/so tall as Li Lei.(4)表示两种情况同时变化。
（the+比较级…, the+比较级越来越……）The busier she is, the happier she feels.The less she worried, the better she worked.(5)A>B>C… (…the+形容词或副词的最高级+in/of/among+比较范围…，最……)He is the tallest of the three.(of表示所有关系时，介词后的词与主语同类。
)Jim writes most carefully in his class. (in表示范围。
)This picture is the most beautiful among these.(among后接代词或没有修饰语的名词。
)(6)A=B>C>D>…（…one of the+最高级+可数名词的复数形式+in/of… ,最……之一）Rose is one of the most careful girls in her class.(7)强调比较程度时，比较级可用的修饰词有：much, far, a lot, a little, a bit,等.Please come here a little earlier.Li Lei jumps much farther than Jim does.(8)形容词比较级+“the”的句型。
He is the cleverer of the two boys.(9)形容词最高级不加“the”的情况。
Today is my happiest day.(10)比较级经典同义句转换1.A horse is more useful than an elephant.= An elephant is a horse.2 . She is the tallest of the three.= She is than the other two .3 .Li Lei runs fastest in his class.= Li Lei runs faster than in his class.= Li Lei runs faster than any of the other students in his class.= Li Lei runs faster than in his class.= Li Lei runs faster than in his class.4 .I think mathematics is more useful than physics.= I d on’t think physics is math.。