Spanish grammar · Beginner

Spanish Indefinite Articles: Un, Una, Unos, Unas

Spanish indefinite articles (un, una, unos, unas) match English a / an / some. They must agree with the noun in gender and number. Often dropped when stating profession, religion, or nationality.

Tengo un libro.

I have a book.

What it is

Spanish indefinite articles (un, una, unos, unas) match English a / an / some. They must agree with the noun in gender and number. The big quirk: Spanish DROPS the indefinite article in several common contexts where English requires it, especially with profession, religion, and nationality.

Tengo un libro (I have a book). Compré unas flores (I bought some flowers). But: Soy profesor (I'm a teacher), no un required.

How to spot it

Look for un / una before singular nouns; unos / unas before plurals. Then check whether the article should actually be there, Spanish often drops it.

  • Quiero un café. — I want a coffee.
  • Tiene una hermana. — He has a sister.
  • Comí unas manzanas. — I ate some apples.

Unos / unas means some / a few, fewer than algunos but more general than algunos.

Spanish Indefinite Articles Quick Reference

Spanish indefinite articles

SingularPlural
Masculineun (a)unos (some)
Feminineuna (a)unas (some)

Common Spanish Indefinite Articles Examples in Spanish

Indefinite articles in use:

Singular: Un / Una

Tengo un coche.
I have a car.
Es una buena idea.
It's a good idea.
Necesito una respuesta.
I need an answer.

Match gender: un (masc.), una (fem.).

Plural: Unos / Unas (Some)

Compré unos libros.
I bought some books.
Vi unas amigas.
I saw some (female) friends.
Hay unos problemas.
There are some problems.

Unos / unas softens the count, roughly some / a few. More definite than algunos.

Drop With Profession / Religion / Nationality

Soy profesor. (NOT soy un profesor)
I'm a teacher.
Es católica.
She's Catholic.
Mi tío es médico.
My uncle is a doctor.

Spanish drops un / una with bare nouns of profession, religion, or nationality. Add it back if modified: Soy un buen profesor (I'm a good teacher).

Drop With Otro / Cierto / Medio

Quiero otro café. (NOT un otro)
I want another coffee.
Cierta persona me llamó.
A certain person called me.
Espero media hora.
I'll wait half an hour.

Otro, cierto, medio, mil, tal already imply indefiniteness, Spanish drops un / una before them.

How to Use Spanish Indefinite Articles

Gender and Number Agreement

Match the noun's gender and number. Masculine sg: un. Feminine sg: una. Masculine pl: unos. Feminine pl: unas.

Un coche, una mesa, unos libros, unas casas.

A car, a table, some books, some houses.

Memorize gender alongside each noun, articles depend on it.

Drop With Profession / Religion / Nationality

After ser, drop un / una before bare nouns of profession, religion, or nationality. Add it back if the noun has an adjective.

Soy abogado. Es católica. Mi padre es médico. BUT: Es un abogado excelente.

I'm a lawyer. She's Catholic. My father is a doctor. He's an excellent lawyer.

Bare noun = no article. Modified noun = bring un / una back.

Drop With Otro, Cierto, Medio, Mil, Tal

These words already imply indefiniteness, so Spanish drops un / una before them.

Otra vez, cierto día, media hora, mil personas, tal cosa.

Another time, a certain day, half an hour, a thousand people, such a thing.

If you'd say un otro in English-influenced Spanish, that's wrong. It's just otro.

Drop in Negative + No / Sin

After no + tener / hay or after sin (without), Spanish often drops un / una.

No tengo coche. Estoy sin trabajo. No hay problema.

I don't have a car. I'm without a job. There's no problem.

Adding un / una emphasizes singularity (No tengo un solo amigo = I don't have a single friend).

Common Mistakes with Spanish Indefinite Articles

Incorrect: Soy un profesor. — I'm a teacher. (wrong in unmodified context)

Correct: Soy profesor. — I'm a teacher.

Spanish drops un / una with bare profession nouns after ser. Add it back only if modified: Soy un buen profesor.

Incorrect: Quiero un otro café. — I want another coffee. (wrong)

Correct: Quiero otro café. — I want another coffee.

Otro already implies indefiniteness, Spanish drops un / una before it. Just otro café.

Incorrect: Compré una manzanas. — I bought some apples. (wrong number)

Correct: Compré unas manzanas. — I bought some apples.

Manzanas is plural, use unas, not una. Match number.

When to Drop the Indefinite Article

Profession / Religion / Nationality (Unmodified)

After ser, drop un / una before bare nouns. Bring it back if there's an adjective.

Soy profesor. → Soy un buen profesor.
I'm a teacher. → I'm a good teacher.
Es católica. → Es una católica devota.
She's Catholic. → She's a devoted Catholic.

Adjective triggers the article, without one, Spanish keeps it bare.

Otro / Cierto / Medio / Mil / Tal

These quantifiers and determiners already convey indefiniteness; drop un / una before them.

Otra vez, otro día.
Another time, another day.
Cierto problema. Media hora. Mil personas.
A certain problem. Half an hour. A thousand people.

Common error: un otro (wrong). Just otro.

Negative + Sin / After Tener

After no tener and sin, Spanish often drops the article.

No tengo coche. Estoy sin trabajo.
I don't have a car. I'm without a job.

Adding un / una emphasizes singularity: No tengo ni un peso (I don't have a single peso).

Spanish Indefinite Articles FAQs

What are Spanish indefinite articles?
Un / una / unos / unas, the equivalents of English a / an / some. They must agree with the noun in gender and number.
When should I drop the indefinite article in Spanish?
Drop un / una with bare profession / religion / nationality nouns after ser (Soy profesor), with otro / cierto / medio / mil / tal (otro día), and often after negatives or sin (No tengo coche).
What's the difference between unos and algunos?
Unos / unas means some / a few, softer, often approximate (Compré unas manzanas). Algunos / algunas means some, slightly more definite, often contrasting with others (Algunos estudiantes llegaron tarde). Both work, but unos is less assertive.
Why do I say un agua but una agua sounds wrong?
Actually, agua takes el / un because it's feminine but starts with a stressed a, for pronunciation. El agua, un agua. Adjectives and plural stay feminine: el agua fría, las aguas.
How can I master Spanish indefinite articles?
Learn each noun with its gender (un coche, una mesa). Practice the drop rule (Soy profesor, not Soy un profesor). Native exposure cements the pattern fast, Parrot's daily content models real-world use.