Adjective Number Agreement

In the previous lesson, you learned that Spanish adjectives must agree with the gender of the noun they describe. In this lesson, you will learn that adjectives must also agree in number — singular or plural.

This means that every Spanish adjective potentially has four forms: masculine singular, feminine singular, masculine plural, and feminine plural.

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The Basic Rule: Adding -s or -es

The rule for making adjectives plural mirrors the rule for making nouns plural:

Ending	Plural Rule	Example
Vowel (-o, -a, -e)	Add -s	alto → altos, alta → altas
Consonant	Add -es	fácil → fáciles, español → españoles
-z	Change -z to -ces	feliz → felices

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Four Forms of -o/-a Adjectives

Adjectives that end in -o (masculine) and -a (feminine) have four distinct forms:

	Singular	Plural
Masculine	alto	altos
Feminine	alta	altas

More Examples — All Four Forms