1 st first 2 nd second 3 rd third 4 th fourth 5 th fifth 6 th sixth 7 th seventh 8 th eighth 9 th ninth 10 th tenth 11 th eleventh 12 th twelfth 13 th thirteenth 14 th fourteenth 15 th fifteenth 16 th sixteenth 17 th seventeenth 18 th eighteenth 19 th nineteenth 20th twentieth 21st twenty-first 22nd twenty-second 23rd twenty-third 24th twenty-fourth 25th twenty-fifth 26th twenty-sixth 27th twenty-seventh 28th twenty-eighth 29th twenty-ninth 30th thirtieth