北师大版英语八年级上册Unit3 原级、比较级、最高级的构成和用法

原级、比较级、最高级的构成和用法回顾：原级的构成和用法l)构成：形容词，副词的原级形式是形容词2)用法：表示双方在程度，性质，特征等某方面相等时，用" as 十原级形容词或副词十as"的结构；表示双方不相等时，用" not so (as)十原级形容词或副词十as"的结构；表示一方是另一方的若干倍时，用"倍数十as十原级形容词或副词十as"的结构．e.g. Ms．Sun speaks English as fluently as you．This building looks not so (as) high as that one．This room is three times as large as that one.1.比较级和最高级的构成1）加-er, -est构成比较级和最高级。

单音节形容词和副词以不发音的-e结尾的high higher highest safe safer safest hard harder hardest late later latest small----smaller----smallest large----larger----largestnew----newer----newest nice----nicer----nicest辅音字母要双写的情况以辅音加-y结尾的情况Big bigger biggest dry drier driest Hot hotter hottest merry merrier merriest Thin thinner thinnest easy easier easiest2) 加more, most构成比较级和最高级多音节的形容词由形容词加-ly构成的副词expensive more expensive most expensiveslowly more slowly most slowlycarefully more carefully most carefullyhighly more highly most highly以-ful, -less, -able, -ous, -ive, -ing等结尾的双元音形容词useless more useless most uselessserious more serious most serious分词形容词tired,pleased及glad,often,real, right,wrong等单音节形容词。

Tired more tired most tiredGlad more glad most glad3）下列形容词、副词的比较级和最高级可有两种构成方法．cruel crueler cruelest more cruel most crueloften oftener oftenest more often most oftenstrict stricter strictest more strict most strictfriendly friendlier friendliest more friendly most friendly4)形容词。

副词的比较级和最高级的不规则构成法Good/well better bestBad/ill/badly worse worstMany/much more mostLittle less leastFar farther/further farthest/furthestOld older/elder oldest/eldest2 比较级的表示法：主语+be+比较级+than…主语+谓语+比较级+than…1)不同主语的比较，①双方比较，表示一方超过另一方时，用"比较级十than"的结构表示He is two years younger than I.②表示一方不及另一方时，用" less十原级十than"的结构表示This room is less beautiful than that one2) 同一主语不同方面的比较She is now happier than she has ever been用于修饰比较级的词：even, （very）much, far, a lot, still, yet. a bit，a little，still，much，yet，by far注意：by far通常用于强调最高级．用于比较级时，一般放在比较级的后面，如在前面，应在二者中间加" the"．如He is taller by far than his brother.He is by far the taller of the two brothers.表示一方超过另一方的程度或数量，可在比较级前加上上述表示程度的副词，以加强语气。

He works even harder than before.4）某些以一or结尾的形容词进行比较时，用to代替than．(这些词有inferior [in'fiəriə]低人一等的| 下等的| 下级的，superior [sju:'piriə]上级的；优秀的，出众的；高傲的，junior（下级的，年少的），senior（年长的，高级的），prior（较早的，在先的）等．Junior school小学，senior school中学例如：He is superior to Mr Wang in mathematics5）在比较从句中为了避免重复，我们通常用that(those)，one(ones)代替前面出现的名词。

that指物，one既可指人，也可指物．that可代替可数名词单数和不可数名词，而one只能代替可数名词.例如：The book on the table is more interesting than that on the desk.A box made of iron is stronger than one made of wood．二，as, little, few, elder等在比较级中的用法。

as 用于比较级1）As +形容词或副词原级+asTom is as tall as Mike.2) as +形容词原形+A+名词+asHe is as good a student as you.3) 倍数+as+形容词或副词原级+asThis room is three times as large as that one.提到倍数用法，补充：表示倍数的比较级有如下几种句型：1) A is three(four，etc) times as big(high，long，wide，etc．) as B．例如：Asia is four times as lareg as Europe，亚洲是欧洲的四倍大．(亚洲比欧洲大三倍．)2) A is three(four，ete) times the size(height，length，width，ete) 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大(四倍高)。

(这座新楼比那座旧楼大三倍[高三倍])．3) 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doublelittle/few和many/much的比较级和最高级以及用法1）little less least修饰不可数名词2）few fewer fewest修饰可数复数名词3）much more most修饰不可数名词4）many more most修饰可数复数名词If you want to be thinner and healthier, you’d better eat less food and take more exercise.3.a bit, a little, not a bit, not a little的用法1）the +比较级+主谓，the+比较级+主谓：越。

越。

The harder he works, the happier he feels.2)比较级+and+比较级：越来越。

The weather is getting colder and colder.4. elder的用法1）不能单独用作表语，因为elder不是真正意义上的比较级My sister is older( than me). My sister is elder(than me)2) 描述家庭人员出生的先后She is the older of the two.他是姐妹中较大的一个。

三．形容词和副词最高级的用法，most/mostly/almost/at most 的含义1.形容词和副词最高级的用法三者或三者以上的比较用最高级。

表示最高程度时，用“the+最高级”的结构表示。

最高级中表示比较范围的常用among, in, of 引导的介词短语或从句表示。

Yesterday was the hottest day of the year.She is one of the most beautiful girls in our school.He works (the) hardest in his class.2. 用于修饰最高级的词最高级可以被序数词以及much, by far, nearly, almost by no means，not quite，not really，nothing like等词语所修饰. 例如：This hat is by far／much／nearly／almost ／not nearly／by no means/not quite／nothing like the biggest．How much did the second most expensive hat coat?The Yellow River is the second longest in China.3. 由ing分词和ed分词演变过来的形容词(包括不规则动词如know→known)只能加more或most来表示它们的比较级和最高级more(most) striking, more(most) interesting, more(most) wounded, more(most)worn等。