An indefinite article indicates “a,” “an,” or “one” person, place, thing, or idea that is not specifically identified. It precedes the noun it modifies and agrees with it in number and gender.
In Spanish, the indefinite article has 4 forms, depending on whether the noun is masculine, feminine, singular or plural.
|Singular||un chico (a boy)||una chica (a girl)|
|Plural||unos chicos (some boys)||unas chicas (some girls)|
Note: Remember, as long as the group of creatures has at least one male member, the masculine plural article is used. Thus, “unos chicos” could refer to a group of 5 boys, or it could refer to a group of 4 girls and one boy.