Indefinite Articles in Spanish

In Spanish, similar to English, nouns use articles. In Spanish, articles are used to communicated noun gender (masculine, feminine) and number (singular, plural). Arcticles are also used to indicate whether a noun is definite or indefinite. There are four indefinite articles in Spanish with are the equivalent to the English "a", "an", and "some" or "a few". There are four indefinite articles.
Singular
Plural
una
(feminine)
unas
(feminine)
un
(masculine)
unos
(masculine)


Indefinite articles must always match the gender (feminine, musculine) and number (singular, plural) of the noun. Review the following examples.

I want to watch a movie.
Quiero ver una película.
I bought some crackers at the store.
Compré unas galletas en la tienda.
There is a dog in the street.
Hay un perro en la calle.
There are a few bears in those mountains.
Hay unos osos en esas montañas.


However, when a noun beginning with a stressed "á", "a", or "ha" is singular and feminine, the masculine indefinite article is used instead of the feminine indefinite article in order to improve pronunciation. However, when the same singular feminine noun is plural, the regular feminine article is used.

Singular
Plural
un agua
unas aguas
un alma
unas almas
un águila
unas águilas