In Spanish, adjectives normally come after the nouns they describe. Adjectives change both with the gender and the number of the noun they describe.

Adjectives that end in o have four forms, which change according to gender and number in exactly the same way as you would expect from nouns.

the crazy cat	el gato loco
the crazy cat	la gata loca
the crazy cats	los gatos locos
the crazy cats	las gatas locas

Adjectives that end in another vowel do not change with gender, but do change with number, by taking an -s at the end.

the big cat	el gato grande
the big cat	la gata grande
the big cats	los gatos grandes
the big cats	las gatas grandes

Most of the adjectives that end in a consonant do not change with gender either, but do change with number, by taking -es at the end. Some do change with gender however, and we will always teach you both the masculine and feminine form of these adjectives.

the social cat	el gato social
the social cat	la gata social
the social cats	los gatos sociales
the social cats	las gatas sociales

Usages of difícil