Indefinite articles: un, una, unos, unas

Q: Can I say Soy un profesor?

Normally you say Soy profesor, with no article for a profession after ser. Add the article only when there is an adjective: Es un profesor excelente.

Q: What is the difference between un and uno?

Uno shortens to un right before a masculine noun: un libro. With no noun after it, use uno: ¿Quieres uno?

Grammar path · Lesson 4 of 86 · Stage A1 · Nouns and articles

Indefinite articles let you say 'a/an' or 'some' when you mention a person or thing for the first time, or when it doesn't matter which one. They must match the noun in gender and number: un for masculine singular, una for feminine singular, unos for masculine plural and unas for feminine plural, as in un libro, una mesa, unos libros, unas mesas. In the plural, unos/unas means 'some' or 'a few', and before a number it means 'about'. The usual confusion is with the definite articles el/la: use un when the listener doesn't know the thing yet, and el when you both know exactly which one.

Practise this lesson · 10 sentences

Form

Masculine singularun + sustantivo masculino singular

Hay un libro en la mesa.There is a book on the table.

Feminine singularuna + sustantivo femenino singular

Ella vive en una ciudad grande.She lives in a big city.

Masculine pluralunos + sustantivo masculino plural

Tengo unos amigos en México.I have some friends in Mexico.

Feminine pluralunas + sustantivo femenino plural

Hay unas flores en la ventana.There are some flowers in the window.

When to use it

Mentioning something for the first time

When the listener doesn't know yet which person or thing you mean, use an indefinite article. After hay you almost always use un/una, not el/la.

Hay un perro en el jardín.There is a dog in the garden.

Mi hermana tiene una casa cerca del mar.My sister has a house near the sea.

Asking for any one item

When ordering, asking for or borrowing something where any one will do, use un/una to mean 'a' or 'one'.

Quiero un café, por favor.I want a coffee, please.

¿Me prestas un lápiz?Can you lend me a pencil?

Saying 'some' or 'about'

Unos/unas before a plural noun mean 'some' or 'a few'. Before a number, they mean 'about' or 'roughly'.

Necesito unos tomates para la salsa.I need some tomatoes for the sauce.

Mi profesora tiene unos cuarenta años.My teacher is about forty years old.

The four forms of the indefinite article

masculine singularun libro

feminine singularuna casa

masculine pluralunos libros

feminine pluralunas casas

Signal words

hay

Don't confuse it with

Definite articles: el, la, los, las

Pick un/una when you introduce something new the listener doesn't know yet, or when any one will do. Once it has been mentioned or both of you know which one, switch to el/la: Tengo un perro. El perro se llama Max.

Frequently asked questions

When do I use un and when el?

Use un when you mention something for the first time or it isn't specific. Use el when the listener already knows which one you mean.

Can I say Soy un profesor?

Normally you say Soy profesor, with no article for a profession after ser. Add the article only when there is an adjective: Es un profesor excelente.

What do unos and unas mean?

Before a plural noun they mean 'some' or 'a few': unos libros. Before a number they mean 'about': unos veinte minutos.

Why is it un aula if aula is feminine?

Feminine nouns starting with a stressed 'a' sound take un in the singular for easier pronunciation: un aula, un águila. The plural still uses unas: unas aulas.

What is the difference between un and uno?

Uno shortens to un right before a masculine noun: un libro. With no noun after it, use uno: ¿Quieres uno?