(四)数词

1. 数词分类：

分类

在句中充当的成分

例词

基数词

主语、表语、宾语、定语、同位语

one, eleven, fifty

序数词

主语、表语、宾语、定语、同位语、状语

second, eighth, fortieth

2．基数词的构成及用法：

类型

构成方法

例词

1-12

单独的词

one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve

13-19

在3-9的词尾加上“-teen”

thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen

20,30,40-90

以“-ty”结尾

twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety

100,1000,1000,000,

1000 000 000,

百，千，百万，十亿都有具体量词

one/a hundred, one/a thousand,

one/a million, one/a billion

21-99

“几十”和“个位”之间用连字符“-”

twenty-three,forty-eight

101-999

“百位”后“十位”前加“and”

826: eight hundred and twenty-six

1,000以上

先从右向左每三位数加一逗号，从右向左第一个逗号为thousand,第二个为million,第三个为billion,然后每三位为一单位从左向右读。

1，234，567，892: one billion, two hundred thirty-four million, five hundred sixty-seven thousand eight hund red and ninety-two

3.序数词的构成：

类 型

构成特点

例词及缩写式

one, two, three

单独记忆

first (1st), second (2nd), third (3rd)

four～nineteen

在基数词尾加-th

fifth (5th), ninth (9th), twelfth (12th)

-ty结尾的词

把y→ie，在基数词尾加-th

twentieth (20th), fiftieth (50th), fortieth (40th)

以1～9结尾的多位数

变个位数为序数词即可

twenty-first (21st), ninety-ninth (99th)

hundred, thousand, million, billion

在基数词尾加-th即可

hundredth (100th) thousandth (1,000th) millionth

(1,000,000th) billionth (1,000,000,000th)

4.序数词的用法：

序号

用法特点

举    例

1

前面要加the

He’s always the first to get to meeting-room.

2

前面用a/an表“又一，再一”

He’d better try a fourth time.