新目标英语八年级英语上册第三单元Section A知识点归纳

八年级英语上册第三单元Section A知识点归纳：1.形容词、副词的比较级的相关知识：（1）。

规则变化：以e结尾的家r，例如：late---later, 以重读闭音节且一个辅音字母结尾的双写这个辅音字母再加er ，例如：big—bigger, thin----thinner, fat---fatter,(闭音节是指音节中的元音字母发单元音短音) ，以辅音字母家y结尾的双音节词，（每个音节之间有很短暂的停顿），把y变i再加er,以ed和ing结尾的形容词在词前加more，例如：tired---more tired , exciting----more exciting, 以ly结尾的副词在词前加more,例如：loudly----more loudly, quietly----more quietly (注意：friendly和lovely 为形容词) 多音节词在词前加more ,例如：popular---more popular（2）.常见不规则变化：good/ well----better , bad/ badly----worse , little----less, far---farther(主要指距离远)，或further(主要指程度深) old—elder (年长的例：my elder brother 我的哥哥)（3）.形容词和副词的前后比较对象要一致（即后面的比较对象要和前面的主语保持一致）例如：Tom has longer hair than his brother .(本句中Tom为主语，所以than 后应该加的是his brother ，而不是his brother’s hair) Tom’s hair is longer than his brother’s .(本句中主语是Tom’s hair, 所以比较的对象应该是his brother’s hair )(4)双方比较表示一方不如另一方时用not as/ so ……as 或者less than 例如：This room is more beautiful than that one .=That room is not as/ so beautiful as this one .= That room is less beautiful than this one.(5) 表示一方随另一方的程度而变化用the +比较级，the+比较级，越……..,越……….例如：The more, the better 越多越好（多多益善）The harder he works, the happier he feels. 及时练习：The more he eats, the _________( fat) he gets. (6)不与其他事物比较，表示本身程度的变化时，用比较级+and+比较级结构。

例如：The weather is getting hotter and hotter.天气正变得越来越热。

The girl becomes more and more beautiful .(7) 通常可以用在比较级前面的词有much, a little, a bit , a lot, even,或名词短语。

例如：Tom is a little than me ,but I am much heavier than him. 例2：I am twenty,my brother is eighteen ,so I am two years old than my brother .(8)特殊疑问句中的两者选择，例如：Which is more outgoing, Tom or Jim?(9) 句尾或句首有of the two……，表示“两者中较……..的一个”限制时比较级前需加上the ,例如：Mary is the taller of the two girls.(注意：此为比较级前使用the 的唯一情况)（10）形容词、副词比较级句子构成，一者：Tom works hard. ------两者：Tom works harder than Jim .(用than 连接比较对象，同时将原句中的形容词或副词变为比较级)11.比较级及时练习题：练习：（2）1. old ______ _ 2. busy _________ 3. thin ________ 4. many _________ 5. slow ________ 6. delicious _________ 7. bright __________ 8. lazy________ 9. safe ________ 10. bad__________ 11. well_________ 12. sad _________（2）用所给词的适当形式填空：1. Bob is ________ ( young ) than Fred ，but __________ (tall) than Fred.2. Yingtian is not as ___________ (tall) asYongxian.3. Almost all the students' faces are the same but Li Deming looks _______ (fat) than before .4. Which is _________ (heavy), a hen or a chicken?5. A dictionary is much _________ (expensive) than a story-book.6. An orange ia a little ______ (big) than an apple, but much ________ (small) than a watermelon.7.Miss Chen is __________ _________than Mr. Wang. (popular)8. Mr. Lin is________ ________ _________ Mr. Brown. (sad)9. Question A is _______ ________ _________ ________ Question B. (important)10. A rose is________ ________ __________ ________ a weed(野草). (beautiful)11. He is ________than any other boy in the class.（clever）12. Tom drives much ________ ________than John. (careful)2.as…….as 的用法(1)as….as….中间接形容词或副词的原级，第一个as为副词，第二个as为介词。

当谓语动词是连系动词时，中间加形容词；当谓语动词为副词时，中间接副词。

例如：Tom is a s tall as me. And he studies as hard as me ,too.如果第二个as后用主格形式，则需要加动词。

例如：Tom is as tall as I am. And he studies as hard as I do.(用do代替前面的动词，如果是三单用does,过去式用did)。

(2)as….as…在否定句中可用so ….as 替换。

意思是前者不如后者。

例如：H e is not as/so tall as me.=I am taller than him.(3)as….as…..中间如果涉及数量或程度时可用much+不可数名词或many+可数名词，例如：He has as many books as his brother. Jane got as much money as his sister.(4)中间加形容词时，还可以加名词，顺序是as+形容词+a/ an+单数名词+as .例如：She is as good a teacher as her mother. 她和她妈妈一样是位好老师。

拓展词组：as soon as……，一…..就………as long as……，只要…….3对应反义词：tall----short, thin----heavy/ fat ,quietly----loudly, long---short,4 .both 的用法both指两者都（1）both与名词代词连用，顺序是both of+the+名词或代词，例如：Both of the cats are lovely. Both也可直接加名词，例如：Both cats are lovely.(2)both与代词直接连用时不能说both+代词，例如both we,both us 都是错误的，要加上of 即both of us 例如：Both of us like sports.(3)both 与动词连用时放在be动词、助动词、情态动词之后，行为动词之前，例如：They are both from Australia. We both like watching TV.(4) both 与not 连用表示部分否定，例如：Both of the doors are not open.两扇门并不都开着。

I don’t know both of you. 我并不都认识你们两位。

（只认识一位）易错点：（5）both 常在句中放在road, street,river 的前面，例如：There are many trees on both sides of the road. (=There are many trees on each/ either side of the road)There are many buildings on both sides of the street.(=There are many buidings on each/ either side of the street.)5.But the most important thing is to learn something new and have fun.本句为主语+连系动词+表语，动词作表语时用动名词或动词不定时，例如：His job is to look after the baby.=His job is looking after the baby.6.本单元中形容词与副词易错点：例1：Tom always makes us happy.(此处happy 修饰前面的宾语us,所以用形容词) 例2：Tom learns English well.(此处用well修饰learns ,表示学得程度)，所以判断句尾是形容词还是副词要看修饰的对象，如果修饰谓语动词则用副词，如果修饰前面的宾语则用形容词。