Is this your first lesson on ordinal numbers? Maybe the second? Or, perhaps it’s the third?

To put it simply, ordinal numbers are used to put things in order. This can be anything from an address to the position a runner finishes in a race.

Ordinal numbers indicate position or order in relation to other numbers.

Cardinal numbers, on the other hand, express a quantity of something.

Ordinal numbers always have a suffix tacked onto the end; cardinal numbers do not.

- first (1st)
- second (2nd)
- third (3rd)
- fourth (4th)
- fifth (5th)
- sixth (6th)
- seventh (7th)
- eighth (8th)
- ninth (9th)
- tenth (10th)
- eleventh (11th)
- twelfth (12th)
- thirteenth (13th)
- twentieth (20th)
- twenty-first (21st)
- twenty-second (22nd)
- twenty-third (23rd)
- twenty-fourth (24th)
- thirtieth (30th)

Here are a few guidelines for determining which suffix to add to a number. 1. When a number ends with 1, the suffix at the end is -st. 2. When a number ends with 2, the suffix at the end is -nd. 3. When a number ends with 3, the suffix at the end is -rd. 4. When a number that ends with 0,4,5,6,7,8 or 9 uses the suffix -th (Including 10th, 100th, etc) 5. An exception to the rules above is when a numeral ends with 11, 12, or 13, which all use the -th suffix.

These rules and the list above should make it simple to determine which suffix you need to turn a cardinal number into an ordinal one.

Have fun forming your first few sentences with ordinal numbers.