First,Second,Third,Fourth,Fifth,Sixth,Seventh,Eighth,Nineth,Tenth,Eleventh,Twelveth,Thirtheenth,Fourteenth,Fifteenth,Sixteenth,Seventeenth,Eighteenth,Nineteenth,Twentieth.1-20序数词.
21-40序数词:Twenty first,Twenty Second,Twenty third.Twenty fourth,twenty fifth,twenty sixth,twenty seventh,twenty eighth,twenty nineth,thirtieth.
Thirty first.fortieth.
40--50:Forty first.fiftieth
Fifty first.Sixtieth