1、数词知识点概述：表示数目多少或顺序先后的词叫数词（umerals）。数词与不定代词很相似，其用法相当于名词与形容词。英汉两种文字在数词方面有较大区别，在英语数词运用过程中应注意表示数目多少的基数词、表示顺序先后的序数词、分数的构成和用法，以及hundred,thousand, million, dozen,和score的复数形式等。1.基数词1).基数词英语表达方式。百位数与十位数之间用and连接；十位与个位之间用“-”连接。(1). 112的基数词是：one 1 two2 three 3 four 4five 5 six 6 seven 7eight 8 nine 9 ten 10eleve
2、n 11 twelve 12(2). 1319, 皆由39加后缀-teen构成，即：thirteen13 fourteen 14 fifteen 15sixteen 16 seventeen 17 eighteen 18nineteen 19(3). 2090等十位数均由29加后缀ty构成，即：twenty20 thirty 30 forty 40fifty 50 sixty 60 seventy 70eighty 80 ninety 90(4). 2129由十位数20加个位数19构成，中间须有连字符“-”，即：twenty-one 21twenty-two 22 twenty-three23
3、 twenty-four 24 twenty-five 25 twenty-six 26twenty-seven 27 twenty-eight28 twenty-nine 29其他的十位数照此类推。(5).百位数由19加hundred构成，如包含十位数及个位数，中间用and连接，也可以不用，如只包含个位数，即十位数为零时，则and不可省。如：a (one) hundred 100 two hundred 200 three hundred 300 seven hundred and eight 708 a (one) hundred (and) forty-five 145 six hunr
4、ed (and) ninety-two 692thousand , million, billion的表达法与hundred相同。2). hundred, thousand , million , billion, dozen和score等量词前有具体数目时，不加s；表不确定数目时，常用复数形式，且与of连用。如：two ( many /several ) dozen books（二十四本书许多打书好几打书） three hundred people（三百人） hundreds of people（几百人） scores /dozens of people（许多人）等。又如：-How many
5、 times have you seen her?-Oh,hundreds oftimes, I think.你见过他多少次？哦，我想有几百次吧。He boughttwo dozencopies of the magazine .他买了两打这种杂志。注：a. dozen表示具体数目时一般后面不加介词of，若dozen位于these, those,them, us前，dozen后必须要加of。如：a dozen of these apples ; three dozen of them by the dozen=in (ones) dozens（成打地）等。又如：Shortly after th
6、e accident,two dozenpolice were sent to the spot to keep order .事故一发生，二十四名警察就被派往出事地点维持秩序。Shortly after the accident,dozens ofpolice were sent to the spot to keep order.事故一发生，许多警察就被派往出事地点维持秩序。b. score表示具体数目时一般后面要加介词of，若score后还有具体数目连用，则不加of如：two score of apples（四十个苹果）three score and ten people（五十个人） b
7、y the score=in (ones) scores（二十二十地）等。又如：There weretwo score ofpeople in the room .房间里有四十人。There aretwo score and tenstudents in our school.我们班上有五十个学生。3).基数词的复数形式表示年代或年龄。如：in the1990s / in the 1990s（二十世纪九十年代）; in ones thirties（三十多岁）in ones teens（十几岁）。又如：When he moved to Germanyin the fifties, he was
8、alreadyin his sixties.当他五十年代搬到德国时，他已经六十多岁了。2.序数词1).序数词英语表达方法序数词第1-19除first, second与third有特殊形式外，其余均由基数词加后缀-th构成；以-y结尾的整十数要变y为i，再加eth。(1). 119的序数词除first, second与third有特殊形式外，其余均由基数词加后缀-th构成：first 1st second 2nd third 3rdfourth 4th fifth 5th sixth 6thseventh 7th eighth 8th ninth 9thtenth 10th eleventh 1
9、1th twelfth 12ththirteenth 13th fourteenth14th fifteenth 15th sixteenth 16th seventeenth 17th eighteenth 18th nineteenth 19th(2).整十数的序数词要变y为i，再加eth。如：twentieth 20ththirtieth 30th fortieth 40th(3).十位数的序数词如包含19的个位数时，十位数用基数词，个位数用序数词，中间须有连字符“-”。如：twenty-first 21st thirty-second 32nd forty-third 43th(4).
10、百、千、万等的序数词由hundred, thousand等加-th，前面加有关的基数词构成。如：(one) hundredth 100th (one)thousandth 1 000th ten thousandth 10000th (one) hundred thousandth 100000th (one) millionth 1 000 000th ten millionth 10 000 000th (one) hundred millionth 100 000 000th(one) billionth 1 000 000 000th注：序数词hundredth,thousandth,
11、 millionth, billionth之前的“一”只可用one，不可用a。(5).多位数序数词的个位数如包含19时，个位数用序数词，前位数用基数词，中间出现零时，须用and连接。如：five million forty thousand two hundred (and) fifty-second5 040 252th four hundred and first 401st3.编号编号有三种表达方式：A .the +序数词+名词(第几) B .a +序数词+名词(再一/另一) C.名词+基数词如：the first lesson（第一课） a third time（再一次，又一次）the
12、 No. 1 Middle School（第一中学） Lesson One(首字大写)（第一课）Room 201（房间）等。又如：We are to studyChapter Fourthis week.我们这周要学第四章。注：当基数词和序数词同时修饰一个名词时，一般序数词在基数词之前。如：the first four pages（前四页）若序数词充当描绘性修饰语时，则放在基数词之后。如：three first prizes（三个一等奖）4.分数的表达方式 分子用基数词，分母用序数，当分子大于1时，分母用复数形式。如：a / one half（二分之一）one third（三分之一） two
13、thirds（三分之二） aone quarter / one fourth（四分之一）two and a quarter（二又四分之一）等。5.百分数的表达方式 %读作percent (或per cent)。如：40%读作forty per cent又如：The population of our village today is70 percentas much as that before liberation .如今我们村庄的人口只有解放前的百分之七十。The production of steel of 2001 isthirty percenthigher than that of
14、 2000 .年的钢产量比高了百分之三十。6.小数的表达方式小数点读作 point如：8.27eight point two seven 0.29 zero point two nine7.年、月、日的表达方式如：December25th , 1999读作December twenty-fifth nineteen-nine或the twenty- fifth of December of nineteen-nine8.时刻的表达方式“过”用“past”，“差”用“to”。如：half past six pm.（下午六点半） five to eight am.（上午八点差五分）9.倍数有三种表
15、达方式X +times (两倍可用twice) + as +形容词或副词原级+ asX times +形容词或副词比较级+ thanX times + the length (width,weight , size of)如：This box isfour times as light asthat one.=This box isthree times lighter thanthat one.=This box isfour times the weight ofthat one.这个盒子比那个盒子轻三倍。The classroom isfive times as large asour office.=The classroom isfour times larger thanour office.=The classroom isfive times the size ofour classroom.这个教室有我们办公室的五倍大。
