1.英语中表示数目的词为基数词，基数词中最基本的是下面这些，所有其他数词都可以由这些构成：
I II III IV
1-one 11-eleven 20-twenty 100
2-two 12-twelve 30-thirty a hundred
3-three 13-thirteen 40-forty 1,000
4-four 14-fourteen 50-fifty a thousand
5-five 15-fifteen 60-sixty 1,000,000
6-six 16-sixteen 70-seventy a million
7-seven 17-seventeen 80-eighty 1,000,000,000
8-eight 18-eighteen 90-ninety a billion
9-nine 19-nineteen
10ten
2.其他基数词的构成方式归纳如下：
1)21—99：先说“几十”，再说“几”，中间加连字号：
38-thirty-eight 96-ninety-six
2)101—999：先说“几百”，再加and，再加末两位数，或末位数：
217-two hundred and seventeen 809-eight hundred and nine
3)1000以上的数，先从后往前数，每三位加“，”，第一个“，”号前为thousand，第二个“，”号前为million，第二个“，”号前为billion(十亿)。然后一节一节地表示(hounded，thousand等词都用单数形式)：
2,003-two thousand and three
9,945-nine thousand.nine hundred and forty-five
174,300 one hundred and seventy-four thousand and three hundred
4,500,000-four million and five hundred thousand
1,300,000,000-one billion and three hundred million
40,000,000,000-forty billion
