数词用来表示人或物的数目多少和顺序。所以数词主要有两种：基数词，用于计数，如：one, two…而序数词用于表示位置先后或次序，台：first? second…其构成法如下：?
阿拉伯数字 基数词 序数词 简写序数词
1 one first 1st
2 two second 2nd
3 three third 3rd
4 four fourth 4th
5 five fifth 5th
6 six sixth 6th
7 seven seventh 7th
8 eight eighth 8th
9 nine ninth 9th
10 ten tenth 10th
11 eleven eleventh 11th
12 twelve twelfth 12th
13 thirteen thirteenth 13th
14 fourteen fourteenth 14th
15 fifteen fifteenth 15th
16 sixteen sixteenth 16th
17 seventeen seventeenth 17th
18 eighteen eighteenth 18yh
19 nineteen nineteenth 19th
20 twenty twentieth 20th
21 twenty-one twenty-first 21st
30 thirty thirtieth 30th
40 forty fortieth 40th
50 fifty fiftieth 50thwww.ExamW.CoM
60 sixty sixtieth 60th
70 seventy seventieth 70th
80 eighty eightieth 80th
90 ninety ninetieth 90th
100 a(one)hundred hundredth 100th
104 one hundred and four hundred and fourth 104th
1000 a(one) thounsand thounsandth 1000th
10000 ten thounsand ten thounsandth 10000th
1000000 one million millionth 1000000th
基数词与序数词都有一定的构成方法，但都有特殊例外的几个字，所以除了要学会一般构成法之外，还要特别记熟一些例外。因它们在考试中出现的频率很高。
