序数词-2025-2026学年七年级英语下册语法知识点全解（译林牛津版）

初一下译林牛津版 【语法专版】 序数词全解 语法专版 【专题】序数词 语法专项突破 考频分析 初一下译林牛津版中，序数词是基础语法模块，考频占词法总量的8%左右，主要分布在单项选择 1-2题)、完形填空(1-2题)、词汇运用(1-2题)。在具体语境题目中，序数词的拼写规则、与定 冠词he的搭配及基数词的区分往往是解题关键。 考查内容 ·序数词构成规则：基数词变序数词的基本变法（如first,.second,third)、特殊变法（如fifth,eighth, ninth,twelfth)及整十数序数词（如twentieth,thirtieth)的拼写 ·序数词功能应用：表示顺序（如日期、楼层、名次）、特指某一事物（如the second chapter)及序数 词前定冠词the与不定冠词a/an的区别（如the first time vs.a second time) 。序数词与基数词辨析：在具体语境中区分基数词表数量（如three books)与序数词表顺序（如he third book)的用法差异 知识点一：序数词的构成及用法 1.基本序数词（1-19) 1.特殊变化：first(1st)、second(2nd)、third(3rd)、fifth(5th)、eighth(8th)、ninth(9th)、twelfth (12h) 2.一般变化：在基数词后加-h→fourth(4th)、sixth(6th)、seventh(7th)、tenth(10th) 3.例句： January is the first month of the year. .He lives on the third floor. 2.整十序数词(20,30..90) 1.变化规则：将基数词词尾的y变为ie,再加-th→twentieth(20th)、thirtieth(30th)、fortieth(40th) 1 初一下译林牛津版 【语法专版】 序数词全解 2.例句： Her birthday is on the twentieth of May. This is the fiftieth anniversary of our school. 3.非整十序数词(21-99) 1.构成方式：基数词”几十”+.-”+个位序数词→twenty-first(21st)、thirty-second(32nd)、foty-fifth (45th) 2.例句： He won the thirty-first prize in the competition. She was born on the twenty-third of March. 4.序数词的用法（前常加定冠词the) 1.表示顺序：用于名词前表'第”→The second lesson is about animals. 2.表示日期：用于月份后表”几日”→We will have a party on October 1st.(October the first) 3.例句 This is the eighth time I've called you today The ninth day of the ninth lunar month is the Double Ninth Festival. 知识点二：序数词的构成与用法 1.基本序数词(1-19) 1.特殊变化（需单独记忆)：lst-first(第一)、2nd-second(第二)、3rd-third(第三)、5th-fifth(第 五)、8th-eighth(第八)、9th-ninth(第九)、12th-twelfth（第十二) 2.一般变化（基数词词尾加-h):4th-fourth(第四)、6h-sixth(第六)、7th-seventh（第七)、10th -tenth(第十)、11th-eleventh（第十一)、13th-thirteenth(第十三)、14th-fourteenth(第十四)、 l5th-fifteenth(第十五)、16th-sixteenth（第十六)、17th-seventeenth(第十七)、18th-eighteenth (第十八)、l9th-nineteenth(第十九) 3.例句： 。January is the first month of the year.(一月是一年中的第一个月。) ●He finished the race in second place.（他以第二名完成了比赛。) 2.整十序数词（20-90) 2 初一下译林牛津版 【语法专版】序数词全解 1.构成规则：将基数词词尾的”y'变为”ie”,再加-th:20th-twentieth（第二十)、30th-thirtieth（第三 十)、40th-fortieth（第四十)、50th-fiftieth(第五十)、60th-sixtieth(第六十)、70th-seventieth (第七十)、80th-eightieth(第八十)、90th-ninetieth(第九十) 2.例句： 。Her grandmother's eightieth birthday is next week.(她奶奶的八十岁生日在下周。) ·The twentieth century was a time of great change.（二十世纪是一个巨变的时代。) 3.”几十几”序数词(21-99) 1.构成规则：基数词”几十几”的结构（十位+个位），序数词只需将个位变为序数词，十位仍用基数 词：2lst-twenty-first(第二十一)、32nd-thirty-second(第三十二)、43rd-forty-third(第四十三)、 54th-fifty-fourth(第五十四)、65th-sixty-fifth(第六十五)、76th-seventy-sixth(第七十六)、87th -eighty-.seventh(第八十七)、98th-ninety-.eighth(第九十八) 2.例句： ·This is the twenty--first lesson in our textbook.(这是我们课本的第二十一课。) 。They live on the forty-fifth floor of that building.(他们住在那栋楼的第四十五层。) 4.序数词的用法 1.表示顺序：用于名词前，通常与定冠词the”连用 例句：The first day of school is always exciting..(开学第一天总是令人兴奋的。) 2.表示日期：月份+序数词（缩写形式中序数词后加'st/nd/rd/h”) 例句：My birthday is on June 15th.(我的生日在6月15日。) 3.表示分数：分子用基数词，分母用序数词（分子大于1时，分母加-$） 例句：She ate one-third of the cake.(她吃了蛋糕的三分之一。)/Two-fifths of the students are from China.(五分之二的学生来自中国。) 4.特殊搭配：用于the+序数词+名词+o do sth”结构，表示”第几个做某事的” 例句：He was the first person to arrive here..(他是第一个到这儿的人。) 知识点三：序数词 1.基本构成（中考必背) 1.1-3特殊记：first(第1)、second(第2)、third(第3)→例句：Today is the first day of school. 2.4-l9加-th:fourth(第4)、fifth(第5)、eighth（第8)、ninth(第9)、twelfth(第12)、sixteenth(第 l6)→例句：Her birthday is on the fifth of May. 3.20及以上：整十去y加-eth(twentieth第20、thirtieth第30)；非整十”整十基数词+连字符+序数 词”(twenty-first第2l、thirty-third第33)→例句：He lives on the twentieth floor. 3 初一下译林牛津版 【语法专版】 序数词全解 2.用法规则（中考核心) l.序数词前通常加定冠词the→例句：The second lesson is very interesting. 2.序数词前有形容词性物主代词/名词所有格时，不加the→例句：This is my third time to visit Beijing. 3.表示'再一、又一，时，用不定冠词aan+序数词→例句：He failed twice,but he wants to try a third time. 4.序数词可缩写(1st,2nd,3rd,4th.21st)→例句：Her birthday is on May5th. 3.常见搭配（中考常考) l.序数词+名词单数→例句：She is the first student to arrive. 2.”the+序数词+名词'表顺序；”a+序数词+名词'表”又一、再一”→例句：He bought a second car last month. 3.用于日期表达：月份+he+序数词（美式可省略the)→例句：We will have a party on October(he) lst. 考法精析 考法一：序数词的构成 核心：根据基数词写出对应的序数词，或根据序数词判断其构成是否正确 真题1（词汇运用）： Write the ordinal number of"twenty"> 答案：twentieth 解析：整十序数词构成规则为将基数词词尾的'y'改为”ie”,再加-th,”twenty”的序数词为twentieth。 真题2（单项选择)： Which is the correct ordinal number of"thirty-five"? A.thirty-fiveth B.thirty-fifth C.thirty-five D.thirty-fives 答案：B 解析：”几十几”序数词只需将个位数变为序数词，five”的序数词为fifh”,故thirty-.five”的序数 词为thirty-fifth。 考法二：序数词构成与用法综合运用 核心：结合序数词的构成规则（特殊变化、整十/非整十变化）及用法（定冠词the、不定冠词a/an、 日期表达)进行综合考查 真题1（语法填空)： Today is my brother's_(twelve)birthday.We will have a party for him. 答案：twelfth 解析：表示，第十二个生日”需用序数词，twelve的序数词为特殊变化twelfth。 4 初一下译林牛津版 【语法专版】 序数词全解 真题2（单项选择)： Our school will celebrate its_anniversary next month. A.fifty B.fiftieth C.fifteenth D.fiveth 答案：B 解析：表示'第五十周年”需用整十序数词，fifty的序数词变y为ie加-th,即fiftieth;A为基数词， C为”第十五”不符合语境，D拼写错误。 考法三：序数词的综合运用与辨析 核心：掌握序数词的构成规则(1-19、整十、几十几)，理解其表示顺序、日期、分数的用法及与基 数词的区别 真题1（单项选择）： My brother was born on July 22nd.So his birthday is on the_of July. A.twenty-two B.twenty-second C.twentieth-two D.twenty-two-th 答案：B 解析：日期表达中”几日”需用序数词，22的序数词为twenty-.second,构成规则为”几十几”的序数 词只需将个位变为序数词，十位用基数词，即twenty(基数词)+second(序数词)。 真题2（语法填空）： This is my uncle's(forty)birthday.He will have a big party. 答案：fortieth 解析：表示'第几个生日”需用序数词，整十序数词变化规则为将基数词词尾y变为ie加-th,foty 的序数词为fortieth。 解题小妙招 序数词构成妙招 序数词构成有规则，一般后面加-h: 特殊变化要牢记，one-first,,two-second,three-hird,five-fifth,eight-eighth,nine-ninth,twelve-twelfth: 整十序数词有变化，y变ie再加-th,如twenty-twentieth,thirty-hirtieth,fifty-fiftieth: 非整十”几十几”序数词，只需个位数变序数，如thirty-five-thirty-fifth,twenty-one-twenty-fist: 序数词用法要注意，表示顺序常加h,日期表达也用它，分数？再一”灵活用。 真题演练 演练一：单项选择试题（共10题) 1.Which is the correct ordinal number of"eight"? A.eightth B.eighth 5 初一下译林牛津版 【语法专版】 序数词全解 C.eightieth D.eightly 2.My birthday is on theof July. A.five B.fiveth C.fifth D.fifty 3.He won theprize in the competition. A.forty B.fortieth C.fourtieth D.fourteenth 4.We will have a trip on theof next month. A.twenty-one B.twenty-first C.twenty-oneth D.twentieth-one 5.This is my time to visit Shanghai. A.one B.first C.the first D.a first 6.National Day in China is on October the_. A.first B.one C.once D.firstly 7.She is student to finish the test. A.the three B.third C.the third D.a third 8.What's the ordinal number of"ninety"? A.ninetieth B.ninetyth C.nineieth D.ninth 9.He lives on the floor of that building. A.thirty-five 6 初一下译林牛津版 【语法专版】 序数词全解 B.thirty-fiveth C.thirty-fifth D.thirty-fiveth 10.Let's read thelesson now. A.twelve B.twelfth C.twelveth D.twelvth 演练二：填空试题（共10题） 1.The(four)day of a week is Wednesday. 2.My father's birthday is on the(twenty)of December. 3.This is the(one)time I've seen such a beautiful sunset 4.She got the(three)place in the singing competition. 5.The meeting will be held on the (eighteen)of next month 6.We need to learn the (five)unit this week. 7.His(sixty)birthday party was very wonderful. 8.The(twenty-two)lesson is about environmental protection. 9.He is the(nine)person to arrive here today. 10.Today is the(forty-five)day of this term. 演练三：语法填空试题（共10空） Dear Tom, I'm glad to tell you about my trip to Beijing.It was my 1.-(two)time to visit the city.On the 2.-(one) day,I visited the Great Wall.I started climbing at 8:00 a.m.and reached the top at 10:30 a.m.Many people said it was their 3.(three)or even 4.(five)time to visit there! On the 5.(three)day,I went to the Palace Museum.It's the 6._(hundred)anniversary of the museum this year.I saw many old things from the Ming and Qing dynasties.The guide told us that the museum has over 1.8 million cultural relics. On the last day,I visited Tsinghua University.I hope to study there in the future,so this trip was very special for me.It was the 7.(eighteenth)of August when I left Beijing.I will never forget this trip! By the way,my birthday is on the 8.(twenty-first)of next month.Will you come to my party?It will be on the 9.-(fifth)floor of my house.I'm sure it will be the 10.-(best)birthday ever! > 初一下译林牛津版 【语法专版】 序数词全解 Yours, Li Ming 答案区 演练-：1B2.C3B4.B5.B6.A7.C8.A9.C10B 1.fourth 2.twentieth 3.first 4.third 5.eighteenth 6.fifth 7.sixtieth 8.twenty-second 9.ninth 10.forty- fifth 1.second 2.first 3.third 4.fifth 5.third 6.hundredth 7.eighteenth 8.twenty-first 9.fifth 10.best 8