智学网整理了关于2021年初中英语语法之数词，期望对同学们有所帮助，仅供参考。
概念：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。
I基数词
1.基数词的构成
（1）1-20
one,two,three,four,five,six,seven,eight,nine,ten,eleven,twelve,thirteen,fourteen,fifteen, sixteen, seventeen, eighteen, nineteen, twenty
（2）21-99 先说几十，再说几，中间加连字符。
23twenty-three,34thirty-four,45fortyfive,56fifty-six,67sixty-seven,78seventy-eight,89eighty-nine,91ninety-one
（3）101999先说几百，再加and,再加末两位数或末位数；
586five hundred and eighty-six,803eight hundred and three
（4）l,000以上,先从右往左数，每三位数加一个,,第一个,前为thousand.第二个,前为
million,第三个,前为billion（美式）或thousand ,million（英式）,然后一节一节地表示。
1,001one thousand and one
9,785nine thousand, seven hundred and eighty-five
18,423eighteen thousand, four hundred and twenty-three
6,260,309six million two hundred and sixty thousand three hundred and nine
750,000,000,000seven hundred and fifty, billion（美式） seven hundred and fifty thousand million（英式）
2.基数词的使用方法
（1）作主语
eg.Four Of them come from Paris.
（2）作宾语
eg.一 How many books would you like？
一I would like two.
（3）作表语
eg.Seven minus two is five.
（4）作定语
eg.There are three people in my family?
（5）作同位语
eg. You two will go swimming with us.
（6）表具体数字时,hundred, thousand ,million用单数。
eg. There are six hundred students in our grade.
（7）表不确定的数字时,数词用复数。若带名词，再加of。 hundreds of（数百,成百上千的）,thousands of（数干,成千上万的）,millions of（数百万）two thousand
Thousands and thousands of people have visited the city.成千上万的人参观了这座城市。
（8）在一些表示一排或一组的词组里；
eg,They arrived in two sand threes.他们三三两两地来了。
（9）表示十的数词的复数可以表示人的岁数或年代。
eg. He is in his early thirties.他有三十来岁（3134岁）：
This took place in the 1930s.这事发生在二十世纪三十年代；
（10）表示时刻
钟点表达法。
顺读法 如：4:30 four thirty 4:45 four forty-five 4:15 four fifteen 倒读法
如：4:30 half past four
4:15 fifteen past four／a quarter past four 4:45 fifteen to five／a quarter to five
eg.I watch CCTV News at seven oclock every evening.
（11）表示百分数
百分数的表达方法是：基数词+ percent（单数形式）+of+名词。如：
Thirty percent of the students in my class are from cities. 我班30%的学生来自城市。
