英语数词表示数目或者顺序,可分为基数词和序数词。基数词及序数词构成见下表:
数字 | 基数词 | 说明 | 序数词 | 说明 |
1 |
one two three four five six seven eight nine ten eleven twelve thirteen |
1—12是单独的数字13—19是基数词加后缀-teen | first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth thirteenth |
1—3是单独的序数词从4开始一般都是基数词加后缀-th |
20 30 40 50 60 70 80 90 |
twenty thirty forty fifty sixty seventy eighty ninety |
表示“几十”要加后缀-ty |
twentieth |
表示“第几十”的序数词的构成是将基数词的词尾-y变成-ie再加-th |
100 | a hundred | hundredth |
(一)基数词从1—100的拼写形式
(1)1—12这几个基数词的拼写须逐个记忆。
—Who has a dictionary,children?
—I have one.
We will have a two-month holiday after the exam.
(2)13—19的基数词都以后缀“-teen”结尾。其中14,16,17,19的词根与4,6,7,9完全相同,而13,15,18的词根与3,5,8不完全相同,要分清。
(3)表示“十”的基数词20—90的词尾都是以“-ty”结尾。其中 60,70,90的词根与6,7,9完全相同,而20,30,40,50,80的词根与2,3,4,5,8略有不同,要特殊记忆。
(4)21—99的拼写规律是:十位数+个位数,中间用连字号“-”连接。如:25→twenty-five;99→ninety-nine等。
(5)100以上基数词的拼法:100→one(a)hundred;1000→one(a) thousand;10,000—ten thousand;100,000→one(a)hundred thousand;1,000,000→one(a)million。
(6)三位数101—999的构成是在百位数和十位数(个位数)之间加and连接。如:145→one(a)hundred and forty-five,508→five hundred and eight。例如:
There are three hundred and sixty-five days in a year.
(7)为了便于认读,一千以上的四位数或四位数以上的阿拉伯数字从后往前每三位数前加“,”。英语中没有“万”这个单位,一千以上而不到一百万的数字都用thousand表示。例如:4,000→four thousand;435,832→four hundred and thirty-five thousand eight hundred and thirty-two;72,624,476→seventy-two million six hundred and twenty-four thousand four hundred and seventy-six。
(8)million,thousand,hundred之后加“s”再加of表示不定数量,如:成百上千→ hundreds of;成千上万→thousands of;成百万计→millions of。
(二)序数词的构成
(1)序数词多数都是由“基数词+th”构成的。“-th”一般读作 //。在句子使用时,序数词前通常须加定冠词the。例如:four→fourth;six→sixth;seven→seventh;ten→tenth。
(2)少数序数词的构成属于特殊情况,需特别记忆。例如:
one→first;two→second;three→third;five→fifth;eight→eighth; nine→ninth;twevle→twelfth。
(3)以y结尾的十位整数,先将y改成i,再加“-eth”,读作/I/。例如:thirty→thirtieth;sixty→sixtieth等。
(4)21以上的非十位整数,要将末尾数改为序数词,前面其他位数仍用基数词。例如:thirty-one→thirty-first;one hundred and seventy-six→one hundred and seventy-sixth。
(5)序数词的缩写形式是由“阿拉伯数字加序数词后面的两个字母构成。例如:
first→1st;second→2nd;third→3rd;fourth→4th;fifth→5th。
(三)数字的表达法及其读法
(1)年份、年代、时期表达法
年份要用基数词,每两位一读。如:1990's读作nineteen nineties(20世纪90年代);in one's twenties(fifties,seventies...)(在某人20多岁时,50,70……);1978(nineteen seventy-eight)。例如:
A UN report says that the world population passed six billion by the end of the twentieth century.
(2)日期表达法
日期要用月份加(日期的)序数词表示,有两种读法,如六月二十日,June 20(应读作June the twentieth或the twentieth of June)。
(3)时刻表达法
①时刻用基数词表示,“几点整”用“基数词+(o'clock)”,如6:00,six(o'clock)。例如:—What time is it,please?—It's five o'clock.
②“几点半”,用“half past...”或“...thirty”表示,如7:30,half past seven或seven thirty。例如:Sara said we would meet at one thirty in front of the museum.
Peter often gets up at six thirty(half past six).
③“几点过几分(不到半小时)”,用“...(分钟)past...(小时)”或“...(小时)...(分钟)”表示,如,8:05,要用five past eight或eight five表示。例如:—What's the English for 6:10?—It's six ten.
④“几点差几分(不到半小时)”,用“……(分钟)to……(小时)”表示,如,8:50,ten to nine;如果是15分或45分,则用quarter来表示,如8:15可用a quarter past eight,8:45则用a quarter to nine等。例如:—The American film“TITANIC”will begin at two this afternoon.Shall we meet at two to two at the cinema gate?
—OK.Let's make it a little earlier.
(4)分数表达法
在分数词中,表示分子时使用基数词,表示分母时用序数词,除分子是“1”的情况外,表示分母的序数词都用复数形式。如六分之一(one-sixth);四分之三(three-fourths)。例如:They account for one-sixth of the population.
(5)数字运算表达法
1+2=3 读作 One plus(and)two is three
8-2=6 读作 Eight minus two is six.
5×6=30 读作 Five times six is thirty
8÷4=2 读作 Eight divided by four is two.
3>2 读作 Three is more than two.
2<3 读作 Two is less than three.
英语中表示“几加几是多少?”时,用“What/How much +is +基数词+and+基数词?”。例如:How much is eleven and nine?It's twenty.
—What's six and five?
—It's eleven.
(6)编号的表示法
编号也要用基数词。简单的编号(一位数或两位数),一般用普通的基数词表示即可。例如:Grade Three;No.15(读作number fifteen)Middle School等。但较长的数字,就用简化的方法去读。如:Room 307(数字读作three o /u /seven);page 135(数字读作one three five),电话号码的读法也是这样。用于编号时,可以和基数词互换。例如:December is the twelfth month of the year.
The second lesson is the most difficult in this book.
Han Meimei and Lucy are good friends.They are in Class Three.
(7)“几个半”的表达法。英语中“几个半”的表达法有两种:“数词+and a half +名词复数”和“数词+名词复数+and a half.如four days and a half/four and a half days.(四天半)。例如:Miss Gao will stay there for about three months and a half.
(8)用于表示次数。表示“一次”,“两次”的单词是once和twice;表示三次以上则用“基数词+times”;表示“每隔多久一次”用“every+基数词+名词复数”。例如:The Olympic Games are held every four years.