Unit 4 语法课件 2025-2026学年人教版八年级英语下册

语 法 课件 Unit 4 The Wonders of Nature 1 一. 大数字的表达与应用 2 大数字的表达与读法 大数字的表达: 1. 从数字的右端向左数,每三位数加一个逗号。 2. 从右端向左端开始,第一个逗号处读thousand(千),第二个逗号处读million(百万),第三个逗号处读billion (十亿)。 3. 读时通常在hundred 后加and,如果读数中百位数为0,则在thousand 后加and。 18,357,089 读作:eighteen million, three hundred and fifty-seven thousand, and eighty-nine。 4. 英语中没有直接表示“万”和“亿"的单位词,而要用thousand和million来表达,如"一万"用"ten thousand"、"一亿"用“one hundred million" 164,213,430-one hundred and sixty-four million, two hundred and thirteen thousand, four hundred and thirty 3 大数字的表达与读法 大数字的用法: 1. 表示确切的数量用: 基数词+hundred/thousand/million/billion+复数; Do you think it is better to travel ten thousand miles than to read ten thousand books? 你认为行万里路比读万卷书更好吗? 2. 表示不确切的数量用: hundreds/thousands/millions/billions+ of + 复数。 Millions of bees are flying in the sky. 数百万只蜜蜂正在空中飞舞。 4 二. 形容词和副词的 比较级与最高级 5 形容词与副词的比较级和最高级 核心用法: 比较级:用于两者之间的比较,表示“一方比另一方更……”。常与“than”连用。 The Yangtze River is longer than the Yellow River in China. The Mariana Trench is deeper than any other part of the ocean. 最高级:用于三者及以上的比较,表示“最……的”(常与 “the” 连用,后接 “in/of”短语限定范围。 Mount Qomolangma is the highest mountain in the world. The Sahara Desert is the largest desert in the world. 6 形容词与副词的比较级和最高级的变化规则 变化规则 例词 一般在词尾直接加-er和-est tall—taller—tallest; light—lighter—lightest 以字母-e结尾的直接加-r或-st nice—nicer—nicest; fine—finer—finest 以辅音字母加y 结尾的词,变y为i加-er或-est heavy—heavier—heaviest; busy—busier—busiest 7 形容词与副词的比较级和最高级的变化规则 变化规则 例词 以重读闭音节结尾且末尾只有一个辅音字母的形容词,双写最后一个辅音字母再加-er或-est。 thin—thinner—thinnest; hot—hotter—hottest 多音节词或部分双音节词的比较级和最高级在其前面加more或most。 beautiful—more beautiful —most beautiful 8 原级 比较级 最高级 单元应用场景 good/well better best The Great Barrier Reef is one of the best places to study marine life. bad/badly worse worst The weather on Mount Qomolangma can get worse quickly. many/much more most The Amazon Rainforest has the most variety of plants and animals. little less least The Dead Sea has less oxygen than other seas, so few fish live there. 形容词与副词的比较级和最高级的不规则变化 原级 比较级 最高级 good/well better best ill/bad/badly worse worst many/much more most little less least old older/elder oldest/eldest far farther/further farthest/furthest 9 二、比较级句型: 二. 比较级句型: 1. 基础句型:比较级+ than ......比......更...... George runs faster than me. 乔治跑得比我快。 2. 变式一:“比较级+ and +比较级”,表示“越来越……”。 当形容词或副词为部分双音节词或多音节词时,用“more and more +原级”表示。 The rain is getting heavier and heavier. 雨变得越来越大。 3. 变式二: “the +比较级...,the +比较级...”,表示“越……,就越……“表示一方的程度随着另一方的变化而变化。 The harder you work, the luckier you will be. 越努力越幸运。 4. 变式三: ” A +谓语动词+倍数 比较级 than + B“, 表示“A是B的……倍……”。 Our school is three times bigger than yours. 我们学校是你们学校的三倍大。 5. 变式四: A +谓语动词+ the 比较级+ of the two...” 表示“A是两者中比较……的一个”,是特指情况。 Kate is the smarter of the two girls. 凯特是两个女孩中比较聪明的一个。 6. 疑问句: “Which/ Who... +比较级, A or B?” Who is more careful, Bob or John? 鲍勃和约翰谁更细心? 特别提醒: 1. 比较级前可以加修饰词, 如even, much, far, a little,a lot等。 My sister’s room is much tidier than mine. 我姐姐的房间比我的整洁得多。 2. 比较的对象必须一致.有时为了避免重复,可以用that 或those 代替前面出现的词,而且that 或those 不能省略。 The population of Suihua is much smaller than that of Harbin. 绥化的人口比哈尔滨的人口少得多。 3. than前后所使用的动词相同时,通常用助动词代替后面的动词或省略后面的动词。 They all think my eyes look bigger than my brother's. 他i都i为我的眼睛比我哥哥的大。 三、最高级句型: 1. 基础句型: the + 最高级 +单数 + in / of 短语, 表示“……中最……的”。 He is the youngest student in our class. 2. 变式一:one of the + 最高级+可数名词复数+ in /of 短语,表示“……中最……的……之一”。 Miss Green is one of the most popular teachers in our school. 3. 变式二: the 序数词+ 最高级+ 单数+in / of 短语, 表示“在……中是第几……的……”(从第二开始)。 As we all know, the Yellow River is the second longest river in China. 4. 疑问句: Which/ Who... + the 最高级, A, B or C ? 表示“A、B、C 中,哪一个/ 谁最……?” Who is the oldest, Tom, Kate or Bill? 四、比较级和最高级之间的转换: 1. A+ 谓语+ 比较级+ than+ any other + 单数 + 范围。 表示“A 是……中最……的”或“A 比(其他)任何……都……”. Shanghai is bigger than any other city in China. 上海比中国其他的任何一个城市都大。 2. A+ 谓语+ 比较级+ than + the other + 复数+ 范围。 表示“A 是……中最……的”或“A 比(其他)任何……都……”. Shanghai is bigger than the other cities in China. 上海比中国其他的任何一个城市都大。 特别提醒: 形容词最高级前必须加定冠词the; 但是当形容词的最高级前已经有了作定语用的形物代或名词所有格时修饰时,不加the; 副词最高级前可以不加the. 一. 单项选择 1. The _ you are, the _ mistakes you’ll make. A. more careful; more B. less careful; fewer C. more careful; fewer 2. Jianshe Road is the _ road in our city, especially around 8:00 am. A. busier B. busiest C. wider D. widest C B 对点突破 3. The Qinghai Lake is _ lake in China. It is in Qinghai Province. A. large B. larger C. largest D. the largest 4. Lingling is one of _ students in my class. She is always ready to offer help. A. helpful B. more helpful C. less helpful D. the most helpful 5. AI technology in China has developed _ than anyone expected. A. fast B. faster C. fastest D D B 对点突破 二. 用括号内所给词的适当形式填空 1. China is one of _ (old) countries in the world. We are all proud of it. 2. The international influence of Yangzhou is getting _(strong) than before. 3. The more we communicate with our parents, the _ (good) we’ll understand each other. the oldest stronger better 对点突破 4. Lin Tao runs _ (fast) than most of his classmates. He is the running star in his class. 5. Of all the vegetables, I think the tomato is the (tasty) and healthiest. faster tastiest 对点突破 $