2. Ordinal numbers can also be called place value numbers. In English, an example is first, second, third. The ordinal numbers come before the noun and must agree in gender.

3. First-primer(o)/a Second-segundo/a Third-tercer(o)/a Fourth-cuarto/a Fifth-quinto/a Sixth-sexto/a Seventh-séptimo/a Eighth-octavo/a Ninth-noveno/a Tenth-décimo/a Eleventh-undécimo/a Twelveth- duodécimo/a

4. When you have a masculine noun following the words first and third, you need to drop the –o. Ex. El primer chico-the first boy El tercer pupitre-the third desk