（一）基数词 在英语中表示数目的词称为基数词。
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。
23→twenty-three,34→thirty-four,45→forty—five,56→fifty-six,67→sixty-seven,78→seventy-eight,89→eighty-nine,91→ninety-one
（3）101—999先说“几百”，再加and,再加末两位数或末位数；
586→five hundred and eighty-six,803→eight 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。
1,001→one thousand and one
9,785→nine thousand, seven hundred and eighty-five
18,423→eighteen thousand,four hundred and twenty-three
6,260,309→six million two hundred and sixty thousand three hundred and nine
750,000,000,000→seven hundred and fifty, billion（美式） seven hundred and fifty thousand million（英式）
2.基数词的用法
（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）
eg,They arrived in two sand threes.他们三三两两地来了。
（8）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（31—34岁）：
This took place in the 1930s.这事发生在二十世纪三十年代；
（9）表示时刻
eg.I watch CCTV News at seven o’clock every evening.
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