基數(shù)詞 序數(shù)詞
1（one) (first)
2(two) (second)
3(three) (third)
4(four) (fourth)
5(five) (fifth）
6(six) (sixth)
8(eight) (eighth)
15(fifteen) ( fifteenth)
19(nineteen) (nineteenth)
20(twenty) (twentieth）
21(twenty-one) (twenty-first)
22(twenty-two) (twenty-second)
30(thirty) (thirtieth)
40(fourty) （fortieth）
50( fifty) ( fiftieth)
90(ninety) (ninetieth)
100(hundred) (hundredth)
105( one hundred and five) (one hundred and fifth)
234(two hundred and thirty-four) (two hundred and thirty-fourth)
基數(shù)詞變序數(shù)詞口訣：
基變序,有規(guī)律,123單獨記,8去t,9去e,f來把ve替,整十將y變ie,后加th要牢記,若是遇到兩位數(shù),十位位基數(shù)詞,個位為序數(shù)詞.