Ordinal Numbers in Spanish

This lesson focuses on the ordinal numbers. These are essentially the adjective form of the cardinal numbers [first, second, third, etc.] As in English, these number forms can be accompanied by the definite article and used as nouns, as well [the first , the second, the third, etc.]

Here are the most commonly used ordinal numbers:
Primero [first]
Segundo [second]
Tercero [third]
Cuarto [fourth]
Quinto [fifth]
Sexto [sixth]
séptimo, sétimo [seventh]
octavo [eighth]
noveno [ninth]
décimo [tenth]

When used as adjectives, these ordinal numbers must agree in gender with the noun they describe.
Example:
El sexto libro.
La sexta película.

Exception: when primero and tercero come before a masculine singular noun, the final -o is dropped.
Examples:
El tercer libro.

Beyond décimo, ordinal numbers are rarely used. More often, the cardinal number is used along with the definite article.
Example:
El siglo veintiuno [The twenty-first century]
El día quince [The fifteenth day]