Explanation

Quick Answer

An adjective is a word that describes a noun. In Spanish, adjectives must agree with the noun they are describing in gender (masculine/feminine) and number (singular/plural).

Adjectives Ending in -o

When you look up an adjective in the dictionary, it is always in the masculine singular form. In other words, it always ends in -o. Adjectives that end in -o have four possible endings, one each for masculine, feminine, singular, and plural. These types of adjectives make up the majority of adjectives in Spanish.

	Singular	Plural
Masculine	-o	-os
Feminine	-a	-as

The following examples demonstrate how to make an adjective that ends in -o agree with a noun.

examples
Ese hombre es muy alto. That man is very tall.
Me gusta la camisa roja. I like the red shirt.
Los vasos están rotos. The glasses are broken.
El jardín está lleno de rosas hermosas. The garden is full of beautiful roses.

Adjectives Ending in -e

Adjectives that end in -e do not change according to gender. They are used with both masculine and feminine nouns in the singular form, though they do change in number.

	Singular	Plural
Masculine	-e	-es
Feminine	-e	-es

Let’s see this in practice.

examples
Ayudé a una tortuga grande a cruzar la calle. I helped a big turtle cross the street.
Los elefantes son grandes. Elephants are big.

Adjectives Ending in -ista

Adjectives that end in -ista follow the same rule as adjectives ending in -e. They only change in number, not gender.

	Singular	Plural
Masculine	-ista	-istas
Feminine	-ista	-istas

Let’s take a look at some examples.

examples
Jorge es muy materialista. Jorge is so materialistic.
No somos personas materialistas. We’re not materialistic people.

Adjectives Ending in a Consonant

Most adjectives that end in a consonant do not have a feminine form, but they do change in number. To make an adjective that ends in a consonant plural, add -es to the singular ending.

examples
La ballena es gris. The whale is gray.
Hay tres camisas azules. There are three blue shirts.

Adjectives Ending in a Consonant: Exceptions to the Rule

Adjectives Ending in -or, -ón, -án, and -ín

Unlike other adjectives ending in a consonant, these adjectives do change in number and gender, so they have four forms. Simply add -a, -es, or -as to the masculine singular form and delete the written accent if necessary.

examples
Mi hermanastro es alemán. My stepbrother is German.
Mi hermanastra es alemana. My stepsister is German.
Mis hermanastros son alemanes. My stepbrothers are German.
Mis hermanastras son alemanas. My stepsisters are German.

Adjectives ending in -erior do not have a feminine form. For example:

el año anteriorthe previous year

la versión anteriorthe previous version

Both masculine and feminine add -es in the plural:

los años anterioresthe previous years

las versiones anterioresthe previous versions

Adjectives Ending in -z

For adjectives ending in -z in the singular, change the z to a c before adding the plural ending.

examples
La leona feroz se abalanzó sobre su presa. The ferocious lioness pounced on her prey.
El hipopótamo es uno de los animales más feroces del mundo. A hippo is one of the most ferocious animals in the world.

Adjectives that Add an Accent in the Plural

The adjective jovenadds an accent in the plural.

examples
Soy joven. I am young.
Los estudiantes son jóvenes. The students are young.

Adjectives ending in -es

Many nationalities in Spanish end in -es, such as francés, japonés, and nepalés. These change in number and gender. However, the adjectives cortésand descortésare an exception and only change in number.

examples
Mi profesora es francesa. My professor is French.
Las chicas japonesas están haciendo sushi. The Japanese girls are making sushi.
Luisa es una persona muy cortés. Luisa is a very polite person.
Sus hijos son descorteses. Their children are impolite.

Noun-Adjective Agreement with Nouns with Irregular Gender

Words beginning with stressed a, such as agua, alma, or hambre, use the article el even though they are feminine. When using these nouns with an adjective, the adjective needs to be in the feminine form.

examples
El agua es cristalina. The water is crystal clear.

Noun-Adjective Agreement with Short-Form Adjectives

Some Spanish adjectives need to be shortened when they come before a masculine singular noun.

For example:

Original Adjective	Short-Form Adjective	Example
primero	primer	Vivo en el primer piso.
alguno	algún	¿Tienes algún problema?

Quite a few common adjectives are shortened when they are used before a masculine and singular noun. Here's a list of some you're likely to come across.

Original Adjective	Short-Form Adjective	English
bueno	buen	good
malo	mal	bad
uno	un	one, a
primero	primer	first
tercero	tercer	third
cualquiera	cualquier	any, whatever
alguno	algún	some
ninguno	ningún	none