英语数词语法详解
2014-04-29 16:37阅读：
一.数词的定义
数词是表示数目多少或先后顺序的词,有基数词和序数词两种。表数量的数词叫基数词，如one, two,
three。表顺序的数词叫序数词，如first, second, third, fourth,
fifth,...
二.基数词
（一）构成
1）1~12单独记
one, two, three, four, five, six, seven,
eight, nine, ten, eleven, twelve
2)13~19词尾为-teen：thirteen, fourteen, fifteen, sixteen,
seventeen, eighteen, nineteen
3)20~90逢整十词尾为-ty：twenty,
thirty,forty,fifity,...
4)21~ 99在十位数和个位数之间加连字符构成，如：
73 seventy-three, 88
eighty-eight
5)101~ 999先说几百，再加and,再加末尾两位数，如：
178 one hundred and
seventy-eight
6)1000以上的数词，先从后向前数，每三位用一个数逗点“，”隔开。第一个“，”是thousand千，第二个“，”是million百万，第三个“，”是billion美语中的十亿（英国用thousand
million），然后一节一节地用几百几十几的方法来数。
注意
①英语中没有“万”，用ten thousand
10,000表示
②十万的表示法：one hundred thousand
100,000
③百万的表示方法：a/one million
1,000,000
④千万及以上的表示法：
2百亿 twenty thousand million（英），twenty
billion（美）
万亿，兆a trillion=a million million
=1012,(旧指-尤英国，百万兆，1018)
（二）基数词的使用
基数词可在句中作主语、表语、定语、状语、介宾、同位语。
Two of them are
students.主语
Two and two are four.
表语
We two joined the
army.同位语
Two thousand people
were present at the
meeting.定语
（三）基数词使用的注意事项
1）hundred, thousand, million, billion,
score(20),dozen(12)前有数词表示具体数目时，这些词不加复数。当前无数词时，这些数词要加复数后再加of
连接名词，来表示不具体量。
如：five hundred people, two score apples, hundreds of
people, scores of pears, thousands of, thousands and thousands of,
tens of thousands of, millions of, a few hundred men, many
thousands of men, some/several million(s of)
men
2)表示“几十”的数词的复数形式前用形容词性物主代词修饰可用来表示“在某人…十几岁时”；用定冠词修饰表示“…年代”。
in one's early
twenties(thirties)在某人二十（三十）几岁时
the 1840's/the 1840s 19世纪40年代
the 1980s/the 1980’s 20世纪80年代
▲十亿以上的大数，英美有不同的表示：
英国英语
美国英语
十亿thousand million
one
billion
百亿ten thousand million
ten
billion
千亿hundred thousand million
one hundred billion
万亿one thousand billion
one
trillion
年代的读法:
297读作two ninety-seven或two hundred and
ninety-seven
1908读作nineteen and
eight或nineteen o eight或nineteen hundred and
eight
1949读作nineteen
forty-nine或nineteen hundred and forty-nine
2000读作two
thousand
4)a.在美国英语中，表示几点过几分可用after,表示几点差几分可用before。如:12点10分：ten
after twelve。11点50分：ten before twelve。
b.若想表明是上午，可在时间后加上am或a. m.(a.m.是拉丁语ante
meridiem的缩写，意为“上午”)，若想表明是下午，可在时间后加上pm或p. m. (p.m.是拉丁语post
meridiem的缩写意为“下午”)。a.m.或p. m.前若是整点，用了a. m.或p. m后，不再用o'clock，也不可加
“：00 ”。如：at 8 a. m.（上午8点），at 5 p. m.（下午5点）。
c.表示“…点整”时，用sharp。如: at nine o'clock
sharp（九点整），at 23:00 sharp（二十三点整）。
5)年龄表达
①表示“…岁”
He is eighteen (years old).
He is aged eighteen.
He is at the age of eighteen. His age is
eighteen.
②表示“快满…岁”
He will be eighteen years old.
He is going on eighteen years old.
He is getting on for eighteen.
It will be his eighteenth
birthday.
③表示“不满…岁”
He is barely/nearly/almost eighteen.
He is not quite/yet eighteen.
He is under/below eighteen.
④表示“已经…岁”可用以下方法表示：
He is past/over/above eighteen.
He is more than eighteen.
He has turned eighteen.
⑤表示大概年龄时用“in one's +基数词复数形式”结构。
a.从十三岁到十九岁，用in one's teens .
b.二十岁以上就用in one's twenties/thirties/forties/fifties
…/nineties，还可以借助early，middle，late来表达得更明确一些。
三.序数词
1）记忆口诀，基数词变为序数词
一二三要单独记：one-first, two-second,
three-third
th要从四加起：four-fourth,
five-fifth,...
eight少个t：eight- eighth
nine去掉e：nine-ninth
ve用f来代替：five-fifth,
twelve-twelfth
ty变成tie：twenty-twentieth
表第“几十几”，基数加序数记心里：twenty-one→twenty-first
2)序数词在句中主要作定语，一般情况下序数词前要加定冠词。Monday is the second day
of a week.
3)序数词前有时加不定冠词，表示“又一、再一”，相当于another。
Would you like a second cup of
tea?
I had a fourth
apple.我(吃了三个苹果后)又吃了一个苹果。
4）first, second等有时可表示一批人或物。
The first milu deer came from China in the
1860s.
最早的麋鹿是在十九世纪六十年代来自中国的。
5）有时序数词作状语，不加冠词。
He came out first in the
contest.
他在比赛中得第一名。
6）first,
second等在用来指“冠军、亚军”等获胜名次时也常不加冠词。
He is first.他是冠军。
四.百分数、分数、小数的构成及用法
1)百分数：基数词加百分号％percent: 89%→eight-nine
percent
2)分数：分子基数词，分母序数词。分子大于1，分母用复数。分子与分母用连字符连接。
1/3: one third,
2/5:
two fifths
3)带分数：基数词 + and +分数表达：5
6/7 : five and
six-sevenths
注意
1/2: a half, one half
1/4: one-fourth, one
/a quarter
3/4: three
quarters
1/3: a third(33.33r
%读作 thirty-three point three three recurring
percent)
3）小数：小数点读作“point”，数字一律用基数词
1.45: one point four
five
4)通常分数、百分数、小数做定语。“分数（百分数）of
+名词”作主语时谓语动词是根据名词确定的，名词为单数动词即用单数，名词为复数动词即用复数动词。
50% apples are
here.
One third apple is
eaten.
★one and a
half后名词用复数，谓语动词一般用单数，不过事实上也可用复数。
五.
加减乘除运算表达
4 + 4＝8：Four plus/added to four equals
eight.
Four and four are eight.
7－3＝4： Seven minus three is
four.
Three from seven leaves four.
8×8＝64：Eight multiplied by eight is sixty
-four.
Eight times eight is sixty
-four.
20÷4＝5：Twenty divided by four is
five.
Four into twenty goes
five.
六、倍数表达
表示倍数时，一倍用once，两倍用twice，三倍以上用“基数词+times'。
1.常用句式：
①...times+ 形容词/副词的比较级＋than...
②...times as+形容词/副词原级+as+...
③...times the size/length/height/width/...of+
n.表示“是…长/高/宽的几倍”
Li Ming runs twice faster than
Lily.
The river is three times longer than that
one.
= The river is three times as long as that
one.
Our classroom is four times as big as
yours.
= Our classroom is four times bigger than
yours.
