Adjectives are frequently descriptive. That is, most often adjectives are used to describe a noun, or distinguish the noun from a group of similar objects. For example, an adjective might describe the color of an object.
the red pen
the blue pen
In Spanish, most adjectives change form, depending upon whether the word they modify is masculine or feminine. Notice the difference between "the tall boy" and "the tall girl."
el chico alto
la chica alta
Adjectives also change form depending upon whether the word they modify is singular or plural. Notice the difference between "the tall boy" and "the tall boys" ; "the tall girl" and "the tall girls."
el chico alto
los chicos altosla chica alta
las chicas altas
Many common adjectives end in -o. These adjectives have four forms. The following words all mean "tall":
alto
alta
altos
altas
The correct form of the adjective depends upon the noun it modifies. Is the noun masculine or feminine? Singular or plural?
libro rojo
red bookpluma roja
red penlibros rojos
red booksplumas rojas
red pens
Notice how the endings of the nouns and these adjectives are similar.
libro rojo
pluma roja
libros rojos
plumas rojas
Adjectives that end in -e also change form for singular or plural. To form the plural, simply add -s.
la chica inteligente
las chicas inteligentes
Adjectives that end in -e do not, however, change form for masculine or feminine.
la chica inteligente
el chico inteligentelas chicas inteligentes
los chicos inteligentes
Similarly, most adjectives that end in a consonant do change form for singular or plural, but do not change for masculine or feminine. To form the plural, add -es.
la chica popular
el chico popularlas chicas populares
los chicos populares
