Artículo Indefinido - Indefinite Article
In English there are two indefinite articles:
a (or an)
some
In Spanish there are four indefinite articles:
| Un | Singular (male) | a man | un hombre | |
| Una | Singular (female) | a door | una puerta | |
| Unos | Plural (male) | some checks | unos cheques | |
| Unas | Plural (female) | some windows | unas ventanas |
Remember in Spanish:
The indefinite article must agree with the gender of the noun