1. Ordinal numbers
2. One-digit numbers
The first three numbers have the endings -st, -nd, -rd.

However, from the fourth onwards, we will take the cardinal number and we will add the ending -th to it.


3. Aspects to be taken into account
In the tens ending in zero, the -y is replaced by an -i and then the ending -eth is added.


In the tens containing numbers 1, 2 and 3 we will add the ordinals first, second and third to them respectively.


4. How are ordinal numbers used?
- To define the position of an element within a sequential order.- How is the race going?- Pedrosa first, Márquez second.
- With dates, to indicate the specific day of a month.- What day is it today?- Today is the 7 th of August.
- To indicate a century or one of the levels in a building (floor).This is the best invention of the 19 th century.John's room is on the seventh floor.
- To indicate the anniversary year of something or someone.- What are they celebrating?- Their fiftieth wedding anniversary.
- To refer to a king, queen or pope.- Who is that woman?- Elizabeth II Elizabeth the Second.
Remember!
The first three numbers have the endings -st, -nd and -rd:
The other numbers adopt the ending -th:
It should be noted that the tens ending in zero adopt the -ieth ending:
Numbers containing units 1, 2, 3 will keep the endings first, second and third respectively:
Except for numbers 11, 12 and 13, which follow the pattern below: