1. Singular Definite Articles
ALL nouns in Spanish have articles (el/los or la/las) before them.
Singular Definite Articles
refers to one noun (person, place or thing)
Masculine/Singular el
Feminine/Singular la
Ejemplo: el chico (the boy)
Ejemplo: la chica
(the girl)

2. Plural Definite Articles
refers to more than one noun (person, place or thing)
Masculine/Plural
los
Feminine/Plural
las
Ejemplo: los chicos (the boys)
Ejemplo: las chicas (the girls)

3. Singular Indefinite Articles
un and una mean a or an
Masculine un
Feminine
una
El ejemplo: un diccionario
(a dictionary)
El ejemplo: una regla
(a ruler)

4. Plural Indefinite Articles
unos and unas mean some
Masculine
unos
Feminine
unas
unos cuadernos
(some notebooks)
unas mochilas
(some backpacks)

5. Making nouns plural If a noun ends in a vowel add –s
diccionario  diccionarios
If a noun ends in a consonant add –es
papel  papeles
If a noun ends in –z, change –z to –c and add –es
lápiz  lápices

6. When to use plural nouns
Use unos with a masculine plural noun
When you refer to a group of people that includes both males and females, the masculine plural is used (unos estudiantes).
In a negative sentence, un, una, unos, unas are often dropped.
¿Necesitas unos cuadernos? No, no necesito cuadernos.