Using Adjectives as Nouns in Spanish

In the Spanish language it's very common to use adjectives as nouns. In fact, in Spanish, almost any adjective can also function as a noun. Adjectives are most frequently used as nouns when referring to something that has already been mentioned or when identifying something both the speaker and listener are familiar with. Consider the following examples.

She wants the green one.
Ella quiere el verde.
They bought the new ones.
Compraron las nuevas.
We saw a big dog and a small one.
Vimos un perro grande y un pequeño.
I bought a pretty cake and an ugly one.
Compré una torta bonita y una fea.
Do you like the red car or the black car? - I like the red one.
¿Te gusta el coche rojo o el coche negro? - Me gusta el rojo.

Forming Nouns from Adjectives

To turn an adjective into a noun, add an article in front of the adjective. Remember, adjectives as nouns must match the previously mentioned noun in both gender and number. Review the following examples.

the black one
el negro
(singular, masculine)
the black one
la negra
(singular, feminine)
the black ones
los negros
(plural, masculine)
the black ones
las negras
(plural, feminine)

the old one
el viejo
(singular, masculine)
the old one
la vieja
(singular, feminine)
the old ones
los viejos
(plural, masculine)
the old ones
las viejas
(plural, feminine)

the cheap one
el barato
(singular, masculine)
the cheap one
la barata
(singular, feminine)
the cheap ones
los baratos
(plural, masculine)
the cheap ones
las baratas
(plural, feminine)

The article, gender and number used to form the "adjective noun" is determined by the noun previously mentioned in the sentence. Consider the following examples.

I wanted to buy the fast car, but I decided to buy the cheap one.
Quería comprar el coche rápido, pero me decidí a comprar el barato.
Do you know the fat man or the skinny one?
¿Conoces al hombre gordo o al flaco?

Adjectives as nouns can also be used in conjunction with demonstrative adjectives when the demonstrative adjective functions as the article of a noun previously mentioned in the sentence. Read and listen to the following examples, then repeat each out loud.

That old man is my uncle.
Ese hombre viejo es mi tío.
That old one is my uncle.
Ese viejo es mi tío.

That pretty girl over there is my sister.
Aquella chica bonita es mi hermana.
That pretty one over there is my sister.
Aquella bonita es mi hermana.

Changes in Meaning

When an adjective is used as a noun, its meaning may change. The following is a list of adjectives whose meanings change when used as nouns. Read and listen to each, then repeat each one out loud.

evil, sickness
el mal

the lost soul
el perdido

broken, torn
the tear
el roto

el decolorante