基数词：One, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, twenty, thirty, forty, fifty sixty, seventy, eighty, ninety, a hundred, thousand, ten thousand 序数词：First, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, twentieth，thirtieth，fortieth，fiftieth，sixtieth，seventieth，eightieth，ninetieth,hundredth, thousandth, ten thousandth
1---12的基数词依次为，one,two,three,four,five,six seven eight nine ten,eleven,twelve.
序数词一般是在基数词的词尾加th,但是有一些是特殊的。1.2.3.5.8.9.12的序数词依次是，first,second,third,fifth,eighth,ninth,twelfth,这些都是没有规律的，要特别记住的，而前边那些加th的，就按规律变化就可以了。
