Spanish indefinite articles: How and when they’re used

In this guide, we’ll review the main rules governing Spanish indefinite articles. Let’s go! 

• What are the four Spanish indefinite articles?
• When to use indefinite articles in Spanish
• When to omit indefinite articles in Spanish
• Indefinite articles in Spanish: exceptions

What are the four Spanish indefinite articles?

Spanish has four indefinite articles: un, una, unos, and unas. The first two of these are singular, while the latter two are plural.

The English translation for the singular indefinite articles, un and una, is “a.” These indefinite articles refer to a singular noun whose specific identity is not known. The plural indefinite articles in Spanish, unos and unas, translate to “some.” These generally refer to uncountable nouns, or nouns with indefinite quantities. 

All Spanish indefinite articles appear before the noun in a sentence. They must agree with the subject in gender (feminine or masculine) and number (singular or plural). 

This rule is summarized in the table below:

	Spanish masculine	Spanish feminine	English
Singular	un	una	a
Plural	unos	unas	some, a few

When to use indefinite articles in Spanish

Let’s look at three major rules that govern when you can use indefinite articles in Spanish. 

1. When talking about a thing or person for the first time 

• Me gustaría comer una manzana. (I would like to eat an apple.) 
• Ayer vi un documental interesante. (I watched an interesting documentary yesterday.)

2. When talking about an approximate number of things or people 

• Fui a España por unos días. (I went to Spain for a few days.)
• He tomado unas fotos bonitas de Madrid. (I’ve taken some nice pictures of Madrid.)

3. When giving more information about the word with the help of an adjective

• Es un excelente pintor. (He’s an excellent painter.)
• Es una mujer hermosa. (She is a beautiful woman.)

When to omit indefinite articles in Spanish

The Spanish language omits indefinite articles more often than English does. Some scholars want Spanish to use them even less, and colloquial usage supports this trend. 

Let’s look at the three rules for when to omit indefinite articles in Spanish.

1. When talking about professions, occupations and nationalities if a noun is not modified

• Es arquitecto. (He’s an architect.)
• Es italiano. (He’s Italian.)

2. When talking about an indefinite amount with ‘hay’ (there is/there are) and other verbs

• Hay agua en la taza. (There’s some water in this cup.)
• ¿Le pones hielo a tu cóctel? (Do you put some ice in your cocktail?)

3. After the verbs ‘llevar’ (to carry/wear) and ‘tener’ (to have)

Note that this rule only applies if there is no adjective modifying the noun, like so:

• Tenemos casa con jardín. (We have a house with a garden.)
• Lleva chaqueta de invierno. (He/she is wearing a winter jacket.)

Indefinite articles in Spanish: Exceptions

If you’re a beginner, the above rules should be enough to help you talk about basic things in daily conversation. But if you’re closer to the intermediate level, it can be useful to know the most common exceptions with indefinite articles in Spanish. 

1. Adding extra focus to individual words

• Es una mujer, una madre, una empresaria, una activista — una persona muy fuerte. (She’s a woman, a mother, an entrepreneur, an activist — a very strong person.)

Normally, you don’t need to use indefinite articles with professions in Spanish. But in this case, the indefinite article is used to add emphasis to each of the woman’s qualities, rather than listing them mechanically.

2. With the verb ‘tener’ to add emphasis to a word in informal Spanish

• Tengo dolor de la rodilla. (I have knee pain.) 
• ¡Tengo un dolor de rodilla! (I have such a knee pain!) 
• Tengo sed (I’m thirsty.)
• ¡Tengo una sed! (I have such a thirst!)

3. Feminine nouns beginning with a stressed letter ‘a’

If a feminine noun starts with the letter “a” and the first syllable carries the vocal stress, the indefinite article una transforms into un. 

• Esto es un aula. (This is a classroom.)
• Son unas aulas grandes. (They are big classrooms.)
• Es un águila preciosa. (That is a beautiful eagle.)
• Son unas águilas grandes. (They are big eagles.)

Why this transformation? Because placing one “a” immediately after another simply doesn't sound natural, and we want to avoid this cacophony. English does just the same, by converting “a” to “an” if the following noun starts with a vowel.

Spanish drops the “a” from the indefinite article, which makes it sound just like the indefinite article for the opposite gender. But don’t be confused, as this only happens in the singular form. The plural forms (unas and unos) don’t present the same issue, as they both end with “s” and thus avoid the unnaturally long “a” and its cacophonous sound. 

Further steps

A solid understanding of grammar is a critical first step towards getting the tricky indefinite articles right. To really understand the full topic of Spanish articles, don’t forget to review definite articles as well. Ready to try it out loud? Consolidate your knowledge by conversing with others in a live Spanish course. Before long, Spanish indefinite articles will no longer be a mystery to you and the fear of using them will become a thing of the past. ¡Feliz aprendizaje! (Happy learning!)