2020湖南专升本网分享：专升本英语语法之基数词和序数词！

一、基数词及其主要用法
表示数目的词称基数词。15 fifteen，几百几千不加s，242 two hundred and forty-two，5058 five thousand and fifty-eight，9，600，000 nine million six hundred thousand
1.基数词可以用于数字的计算。
6+8=14 Six plus eight is fourteen.
9-7=2 Nine minus seven is two.
7X5=35 Seven times five is thirty-five.
8÷4=2 Eight divided by four is two.
2.基数词可以表示人的大致年龄和年代。
He died in his fifties.
This took place in 1990s/1990s.
The professor became successful in his thirties.
3.基数词可以用来表达年份、时间、电话号码。
1700 seventeen hundred
2014 eighteen fourteen
9：20 nine twenty
11：30 eleven thirty/half past eleven
5：45 five forty-five/a quarter to six
88760231 eight eight seven，six zero two，three one
4.基数词可以用于编号。
Number six，line 4，page 19，Bus(No.)332，Platform(No.)5，Room 101
5.基数词可以和其他词一起构成合成形容词，在句子中作定语。
A one-month-old baby can recognize its mother by smell.
This eleven-month-old baby can speak a few words.
(The baby is eleven months old.)
The teacher asked us to write a four-thousand-word essay as our homework.
(There are four thousand words in the essay.)
This four-paragraph essay is too difficult for me to understand.
(There are four paragraphs in this essay.)
湖南专升本网分享：专升本英语语法之基数词和序数词！
二、序数词及其主要用法
表示顺序的词称为序数词。如first，second，third，fourth，ninth，twenty-first，forty-fifth等。
序数词可以用来表示日期和世纪。May the first/the first of May(5.1)，August the eighth/the eighth of August(8.8)，the twentieth century，the twenty-first century
序数词在句子中前面一般加the
The first of October is our National Day.
She was the third to arrive.
序数词在句子中前面加不定冠词，表示“再一”又一“。
Theyll have to do it a second time.
Shall I ask him a third time?
When he sat down，a fourth man rose to ask.
三、分数词的构成
分数的分子用基数词表示，分母用序数词表示，若分子大于1，分母需用复数。
two-thirds(2/3)，one-third(1/3)，nine-tenths(9/10)，five-twelfths(5/12)。
特殊表达法有：one half(1/2)，a quarter(1/4)，three quarters(3/4).
考试重点
基数词可以和其他词一起构成合成形容词，在句子中作定语，名词不能加s.
数词部分需特别注意dozen，hundred，million，billion等词。表示具体数字时，这些词用单数形式，表示不具体的数字时，须用dozens of，hundreds of这类的结构。
I want three dozen of these.
He has been there dozens of times.