数词概念

数词（Numerals） 是英语中用于表示 数量（基数）或顺序（序数） 的词类，通常用于描述数字、计数、顺序等。
例如：
基数词（Cardinal numbers）： one, two, three, four…
序数词（Ordinal numbers）： first, second, third, fourth…
数词在句子中可以充当主语、宾语、定语、表语等，常用于数学、时间、日期、顺序、数量等场景。

数词分词

基数词

基数词表述数量，如：one, two, three, four…

用法
1.表示确切的数量
There are five apples on the table.（桌子上有五个苹果）
I have two sisters.（我有两个姐姐）

2.作主语、宾语或表语
Three of them are absent.（他们之中有三个缺席。）
She has one dog and two cats.（她有一只狗和两只猫。）

3.用于年、日期、电话号码
He was born in 1995.（他出生于1995年。）
Call me at 555-1234.（请拨打555-1234联系我。）

4.大数的表达
Hundred（100）、Thousand（1,000）、Million（1,000,000）：
There are three hundred students in the school.（学校里有三百名学生。）
He has saved two million dollars.（他存了两百万美元。）

序数词

序数词 表示顺序，如：first, second, third, fourth…
用法
1.表示顺序
He won first prize in the competition.（他获得了比赛的第一名。）
My birthday is on the twelfth of July.（我的生日是7 月 12 日。）

2.用于日期
July 4th is Independence Day in the US.（7 月 4 日是美国独立日。）
Today is the first of September.（今天是9 月 1 日。）

3.用于分数
One-third of the students are absent.（三分之一的学生缺席了。）

4.用于国王、教皇、皇帝的名称
Queen Elizabeth II (the second)（伊丽莎白二世）
Louis XIV (the fourteenth)（路易十四世）

5.与“the”搭配
He was the third to arrive.（他是第三个到达的。）

基数与序数词的区别

基数词（Cardinal）	序数词（Ordinal）
表示数量	表示顺序
one, two, three…	first, second, third…
I have three books.	This is the third book.

基变序的规律

1.大部分序数词加 “-th”
four → fourth
six → sixth
ten → tenth

2.特殊变化
one → first
two → second
three → third
five → fifth（去掉 “e”）
nine → ninth（去掉 “e”）
twelve → twelfth（去掉 “ve” + “f”）

3.以 “y” 结尾的，变 “y” 为 “ieth”
twenty → twentieth
thirty → thirtieth

常用基数词序数词中英对照表

基数词（Cardinal）	序数词（Ordinal）
0 - zero	0th - zeroth（极少用）
1 - one	1st - first
2 - two	2nd - second
3 - three	3rd - third
4 - four	4th - fourth
5 - five	5th - fifth
6 - six	6th - sixth
7 - seven	7th - seventh
8 - eight	8th - eighth
9 - nine	9th - ninth
10 - ten	10th - tenth
11 - eleven	11th - eleventh
12 - twelve	12th - twelfth
13 - thirteen	13th - thirteenth
14 - fourteen	14th - fourteenth
15 - fifteen	15th - fifteenth
16 - sixteen	16th - sixteenth
17 - seventeen	17th - seventeenth
18 - eighteen	18th - eighteenth
19 - nineteen	19th - nineteenth
20 - twenty	20th - twentieth
21 - twenty-one	21st - twenty-first
22 - twenty-two	22nd - twenty-second
23 - twenty-three	23rd - twenty-third
24 - twenty-four	24th - twenty-fourth
25 - twenty-five	25th - twenty-fifth
30 - thirty	30th - thirtieth
40 - forty	40th - fortieth
50 - fifty	50th - fiftieth
60 - sixty	60th - sixtieth
70 - seventy	70th - seventieth
80 - eighty	80th - eightieth
90 - ninety	90th - ninetieth
100 - one hundred	100th - hundredth
101 - one hundred and one	101st - hundred and first
200 - two hundred	200th - two hundredth
1,000 - one thousand	1,000th - one thousandth
10,000 - ten thousand	10,000th - ten thousandth
100,000 - one hundred thousand	100,000th - one hundred thousandth
1,000,000 - one million	1,000,000th - one millionth