小学英语数词

数词专项 

表示数目多少或顺序多少的词叫数词，数词分为基数词和序数词。表示数目多少的数词叫基数词；表示顺序的数词叫序数词。

一、基数词

1）基数词写法和读法： 345 three hundred and forty-five；

2）基数词一般是单数形式，但下列情况，常用复数：

a. 与of 短语连用，表示概数，不能与具体数目连用，如scores of people 指许多人；

b. 在一些表示"一排"或"一组"的词组里；

如：They arrived in twos and threes. 他们三三两两的到达了。

c. 表示"几十岁"；

d. 表示"年代"，用 in +the +数词复数；

二、序数词

序数词的缩写形式： first---1st second---2nd thirty-first---31st

三、数词的用法

1. 基数词的用法

(1) 基数词在句中主要用作主语、宾语、定语、表语、同位语，

例如：Thirty of them are Party members. （主语）

--- How many would you like ？

--- Three，please．（作宾语）

The nine boys are from Tianjing. （定语）

Six plus four is ten. （表语）

We four will go with you. （同位语）

(2) 表示一个具体数字时， hundred, thousand, million 不能用复数；在表示一个不确定数字时则用复数。

例如：Our country has a population of 1,300 million people.
There are three thousand students in our school.
After the war, thousands of people became homeless.
Maize is the most important food crop for millions of people in the world.
They arrived in twos and threes

There are three thousand students in our school.

After the war, thousands of people became homeless.

Maize is the most important food crop for millions of people in the world.

They arrived in twos and threes．

(3) 表示 “…… 十”的数词的复数形式可用来表示人的岁数或年代，

例如：He is in his early thirties．

He died still in his forties．

This took place in 1930s．

(4) 表示时刻用基数词。

例如：We get up at six.
The workers begin work at eight.

The workers begin work at eight.

表示“几点过几分”，用介词 past, 但须在半小时以内。

例如：ten past ten,
a quarter past nine,
half past twelve

a quarter past nine,

half past twelve

表示“几点差几分”用介词 to, 但分数须在半小时以上。

例如：twenty to nine,
to eight,
a quarter to ten

to eight,

a quarter to ten

表示“几点几分”还可直接用基数词。

例如：seven fifteen,
eleven thirty,
nine twenty

eleven thirty,

nine twenty

2. 序数词的用法

（1）序数词主要用作定语，前面要加定冠词，

例如：The first truck is carrying a foot baskets ．

John lives on the fifteenth floor ．

（2）序数词有时前面可加不定冠词来表示“再一”，“又一”这样的意思，

例如：We'll have to do it a second time ．

Shall I ask him a third time ？

When I sat down ，a fourth man rose to speak ．

（3）由几个序数词和基数词在拼写时不对应，很容易写错，应特别注意。

它们是： one---first, two---second, three---third, five---fifth, eight---eighth, nine---ninth, twelve---twelfth 。

（4）表示年，月，日时， 年用基数词表示，日用序数词表示。

例如：1949 年十月一 日 读作：October (the) first, nineteen sixty

2004 年九月十 日 读作：September (the) tenth, two thousand and four

（5）表示分数时，分子用基数词表示，分母用序数词表示。分子大于 1 时，分母加 -s 。

例如：three fourths,one second,two fifths

（6）序数词有时用缩写形式：

first→1st second→2nd

third→3rd fourth→4th

thirty-second→32nd