Unit 1 Not Too Short not assoas 同级比较否定式-2025-2026学年八年级英语下册语法知识点全解（教科版五四制）

初中教科版（五四制）8下Unit1 【寒假专版】 A版知识点全解 寒假专版 【专题】not as/soas同级比较否定式 语法专项突破 考频分析 教科版（五四制）8下中，not as/so.as同级比较否定式是重点语法点，考频占句法总量的10%左 右，主要分布在核心题型：单项选择(1-2题)、完形填空(1-2题)、语法填空(1题)。在语境理 解类题目中，该结构的正确运用及与as.as肯定式的辨析往往是解题关键。 知识点二：not as/so..as同级比较否定式用法 1.基本结构及含义 1.结构：主语+be动词/实义动词+not as/so+形容词/副词原级+as+比较对象 2.含义：表示“前者不如后者…”，as.…as用于肯定句，not as/so.…as用于否定句(s0更口语化) 3.例句： ·This story is not as interesting as that one.(be动词+形容词原级；这个故事不如那个有趣) ·He does not run so fast as his brother.(实义动词+副词原级：他跑得不如他哥哥快) 2.不同词性的用法 1.修饰名词时（形容词原级+名词）： ·结构：主语+be+not as/so+形容词原级+a/an+可数名词单数+as+比较对象 。例句：She is not as smart a student as her sister..(她不如她姐姐聪明) 2.修饰实义动词时（副词原级）： 。结构：主语+助动词(do/does/did)+not+实义动词原形+so/as+副词原级+as+比较对象 ●例句：They did not play basketball so well as we did yesterday.(他们昨天篮球打得不如我们好) 3.常见误区及注意事项 1.避免误用比较级/最高级：必须使用形容词/副词原级，不可用taller、fastest等 。错误：He is not as taller as me.(×)→正确：He is not as tall as me.(√) 初中教科版（五四制）8下Unit1 【寒假专版】 A版知识点全解 2.as/so和as不可省略：否定句中需完整保留not as/so.as结构 ·错误：She runs not fast as Lily.(×)一正确：She does not run as fast as Lily..(√) 3.比较对象一致性：前后比较对象需为同类事物（人/物/行为等） 。例句：The weather in Beijing is not as warm as that in Guangzhou.(用that指代不可数名词weather, 避免重复) 知识点三：not as/so.as同级比较否定式 1.基本结构及用法（核心语法) 基础结构：A+be动词/实义动词+not as/so+形容词/副词原级+as+B →表示“A不如B…”,as.as用于肯定句，so.as用于否定句（否定句中两者可互换) 例句： 1.形容词比较（修饰名词）：This book is not as/so interesting as that one.(这本书不如那本书有 趣。) 2.副词比较（修饰动词）：He runs not as/so fast as his brother.(他跑得不如他哥哥快。) 2.句式转换（中考必练) 1.肯定句变否定句：直接在be动词/助动词后加not ·原句：She is as tall as her sister.(她和她姐姐一样高。) ·否定句：She is not as/so tall as her sister.(她不如她姐姐高。) 2.实义动词句式：借助助动词do/does/did+not ●原句：Tom studies as hard as Lucy..(汤姆和露西学习一样努力。) ·否定句：Tom does not study as/so hard as Lucy..(汤姆学习不如露西努力。) 3.常见误区及辨析（中考易错） 1.避免误用比较级：not as/so...as中必须用形容词/副词原级，不可用比较级 ·错误：He is not as taller as me. ●正确：He is not as tall as me.(他不如我高。) 2.与“less.…than”的转换：部分语境中可与“less+原级+than”互换，但语气有差异 ·not as/soas强调“不如”，less.than强调“不及” 。例句：This movie is not as/so interesting as that one.=This movie is less interesting than that one.(这 部电影不如那部有趣。) 2 初中教科版（五四制）8下Unit1 【寒假专版】 A版知识点全解 3.倍数表达：倍数词需置于as前 。例句：This room is not twice as big as that one.(这个房间不如那个房间两倍大。) 解题小妙招 not as/so.as解题妙招 be动否定加not,ism't/aren't/wasn't/weren't看主语单复时态： 实义动词要借助，don't/doesn't/didn't后接动词原形： 否定结构not as/so.as,形容词副词用原级： 同义转换less.…thn,原级不变直接替换： 倍数表达放as前，“倍数词+as+原级+as”要牢记： 比较对象需一致，as连接不可替。 考法精析 考法一：基本结构及否定形式运用 核心：根据主语后的动词类型(be动词/实义动词)，正确使用not as/so.as结构表达“甲不如乙”， 掌握be动词和实义动词的否定形式变化规则 真题1（语法填空）： This story(not be)as interesting as that one.I like that one better. 答案：isnt 解析：主语This story为单数，be动词用is,否定形式直接在is后加not,缩写为is't;as后接形 容词原级interesting,符合结构要求。 真题2（单项选择）： She-play the piano so well as her sister. A.don't B.doesn't C.isn't D.not 答案：B 解析：句中play为实义动词原形，否定需借助助动词：主语She为第三人称单数，一般现在时助动 词用does,否定形式为doesn't,符合“助动词+not+动词原形”的结构。 考法二：否定结构与同义转换 核心：掌握not as/so..as的否定结构及与less.than的同义替换规则，准确转换句式 真题1（句型转换）： This story is not as exciting as that one..(改为同义句) This story is_than that one. 答案：less exciting 解析：not as+形容词原级+as可转换为less+形容词原级+han,exciting为多音节形容词，直接 初中教科版（五四制）8下Unit1 【寒假专版】 A版知识点全解 加less。 真题2（单项选择)： He doesn't study so hard his sister. A.as B.than C.so D.more 答案：A 解析：not so.as为固定搭配，表示“不如…”，此处需用as连接比较对象，符合“实义动词+not so叶副词原级+as”结构。 考法三：not as/,so.as句式的综合应用与转换 核心：掌握not as/soas基本结构、与less.…than的转换及否定前移用法，能结合语境判断比较对象 并正确使用原级。 真题1（单项选择)： I don't think this movie isthat one we saw last week. A.so interesting as B.as more interesting as C.less interesting than D.so faster as 答案：A 解析：否定前移结构中，从句需用not as/so...as原级比较，排除B、D项(B项误用比较级，D项 误用副词比较级)：C项虽为同义转换，但题干已有否定前移标志”don't think”,若选C则语义重复 (双重否定)，故选A。 真题2（语法填空)： This red sweater is not as-(expensive)as the blue one,but I like it better 答案：expensive 解析：not as.as结构中需用形容词原级，expensive为多音节形容词，无需变化，直接填原级。 真题演练 演练一：单项选择（共10题） 1.This book_as interesting as that novel.I prefer the novel. A.isn't B.don't C.doesn't D.not 2.She speak English so fluently as her brother. A.isn't B.doesn't C.don't D.not 3.The weather in Xi'an is not so hot_that in Chongqing. A.as B.than C.so D.more 4.He runs not as_as his father A.faster B.fast C.fastest D.the fastest 5.My bag is not as heavy_yours. A.so B.as C.than D.more 4 初中教科版（五四制）8下Unit1 【寒假专版】 A版知识点全解 6.They_work so carefully as we do. A.didn't B.doesn't C.don't D.aren't 7.This story is less exciting-that one. A.as B.than C.so D.more 8.I don't think math is difficult as physics. A.so B.as C.than D.more 9.The population of this town is not twice as_as that city. A.large B.larger C.largest D.the largest 10.She sings not so_as her sister. A.good B.well C.better D.best 演练二：填空试题（共10题） 1.This pen-(not be)as expensive as yours.I bought it for 5 yuan. 2.He_(not run)so fast as his friend.He needs more practice. 3.The film is not as(interest)as the book.I like reading better. 4.My room is less_(big)than my brother's.His room is 20 m2. 5.They_(not study)as hard as their classmates.They often play games. 6.The weather here is not so(warm)as that in Hainan in winter 7.She_(not dance)so beautifully as Mary.Mary won first prize 8.This shirt is not as(cheap)as that one.That one is 30 yuan cheaper. 9.We _(not finish)the work so quickly as they did yesterday. 10.The story is less_(move)than the one we heard last week 演练三：语法填空（共10空） 阅读下面短文，在空白处填入括号内单词的正确形式或根据上下文填入适当的词。 Linda is a student in Grade 8.She thinks English is not as_(easy)as math.Her math teacher often says she is clever,but her English is less_(good)than her classmates.Linda_(not speak)English so fluently as Mary,who isfrom America.Mary'spronunciation is better,andshereads English(loudly)than Linda. One day,Linda asked Mary,"Why is your English so good?"Mary smiled and said,"I practice every day.English is not as(difficult)as you think.You just need to read more."Linda decided to try harder.She reads English for 30 minutes every morning and listens to English songs.Now,her English is improving.Last week,she got an A in the English test,which is not as_(bad)as before.Her teacher said,"Linda,your English is not so(poor)as it was.Keep working hard!" 5 初中教科版（五四制）8下Unit1 【寒假专版】 A版知识点全解 Linda is happy.She knows that with practice,nothing is too difficult.She hopes her English will be as_ (good)as Mary's one day.She also leamns that comparing herself with others is not as(important)as improving herself. 参考答案 演练-：1.A2B3.A4B5B6.C7B8.A9.A10B 演练二：1.isn't2.doesn’trun3.interesting4.big5.don't study6.wam7.doesn't dance8.cheap 9.didn't finish 10.moving 1.easy 2.good 3.doesn't speak 4.more loudly 5.difficult 6.bad 7.poor 8.good 9.important 6