Los ordinales
De Englishwiki: Gramática y vocabulario inglés
Los números ordinales son aquellos que expresan ideas de orden o sucesión. En inglés se forman añadiendo la terminación -th a los cardinales.
1st - first 2nd - second 3rd - third 4th - fourth 5th - fifth 6th - sixth 7th - seventh 8th - eighth 9th - ninth 10th - tenth 11th - eleventh 12th - twelfth 13th - thirteenth 14th - fourteenth 15th - fifteenth 16th - sixteenth 17th - seventeenth 18th - eighteenth 19th - nineteenth
20th - twentieth 21st - twenty-first ...
100th - one hundredth 1,000th - one thousandth 1,000,000th - one millionth