Ordinal Numbers

To form an ordinal number (ordinal numbers put things in order), add the ending -th to the cardinal number.


seven–>seventh
thirteen–>thirteenth


When a cardinal number ends in -y, the -y changes to -ie before adding -th.


twenty–>twentieth
sixty–>sixtieth


Note the following exceptions: first, second, third (sometimes abbreviated as 1st, 2nd, 3rd) and fifth, ninth, twelfth.


twenty-first
forty-third
sixty-fifth


All others are abbreviated as follows: 4th, 5th, 20th, etc.