基数词序数词的特殊用法

基数词在用来表示准确数字的情况下不能加复数后缀"s"。

以下基数词可以加复数后缀"s"，因为它们表达的都是大概的数字。

1.thousands of / millions of / hundreds and hundreds of / hundreds of thousands of / thousands upon thousands of 成千上万……
例：There are hundreds of thousands of people in the park. 公园里的人有千百个。

2. in twos and threes 三三两两
例：They came home from church by twos and threes. 他们三三两两地从教堂回来。

3. at sixes and sevens 乱七八糟
例：His wife was away and the house was at sixes and sevens. 他妻子不在，家里乱七八糟的。

4. in one's fifties 在五十多岁时（fifties 前可插入early, late, mid-, middle)
例：The boys are all in their teens. 那些男孩年纪都在十几岁。

Jane is only in her early forties. 简才刚刚四十出头。

She was in her mid-twenties. 她有二十五、六岁。

He was then in his late seventies. 他当时已经快八十岁了。

5. in the 1960s (in the 1960's) 二十世纪六十年代
例：He made acquaintance of her in the 1960s. 六十年代他认识了她。

数词
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：345three 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score s 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；
e. 在乘法运算的一种表示法里，如：3 x 5 = 15 Three fives is (are) fifteen.
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）倍数表示法
a. 主语+谓语+倍数（或分数）+ as + adj. + as
I have three times as many as you. 我有你三倍那么多。

b. 主语+谓语+倍数（分数）+ the size (amount，length…) of…
The earth is 49 times the size of the moon. 地球是月球的49倍。

c. 主语+谓语+倍数（分数）+ 形容词（副词）比较级+ than…
The grain output is 8 percent higher this year than that of last year. 今年比去年粮食产量增加8%。

d. 还可以用by+倍数，表示增加多少倍
The production of grain has been increased by four times this year. 今年粮食产量增加了4倍。

2）分数表示法
构成：基数词代表分子，序数词代表分母。

分子大于1时，分子的序数词用单数，分母序数词用复数：
1/3 one-third
3/37 three and three-sevenths
一、注意基数词与其他词连用时的位置关系：
The first two years have been very successful.
开头两年非常成功。

Look at the three young men.
看那三个年轻人。

These are for my two daughters.
这些是给我那两个女儿的。

Any two people will do.
任何两个人都可以。

二、修饰语表示大致的量：
about 大约approximately大约around 大约
or so 左右roughly约略some 大约
There were roughly 500 people.
大约有500人。

The time is approximately ten o'clock.
这会儿约莫十点钟。

It'll only cost 15 dollars or so.
只要十五美元左右。

三、修饰语表示最小量：
a minimum of 至少at least 至少more than 多于
or more 或更多over 多于plus 多于
You must get a minimum of 40 questions right to pass the examination. 你最少必须答对40道题才能通过考试。

It costs over ten dollars.
它值十多美元。

All the children here are 12 plus.
这些孩子年龄都在12岁以上。

四、修饰语表示最大量：
almost 差不多nearly 将近a maximum of 最多at most 至多less than 少于or less 或少于under 低于up to 到……之多
I can swim a maximum of 1 mile.
我游泳最远游一英里。

She is nearly fifty now.
她将近五十岁了。

My shirt cost under two pounds.
我的衬衫价钱不到两英镑。