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.
(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.