Articles — el, la, los, las / un, una

Definite (the) and indefinite (a/an/some) articles change for both gender and number, and two of them contract with a and de.

In English there is one definite article (the) and the indefinite a/an. Spanish has a fuller set: articles change to match the gender (masculine/feminine) and number (singular/plural) of the noun they introduce.

This is actually helpful — the article gives you information about the noun before you even reach it. If you hear 'las', you already know what follows is feminine and plural.

There are also two small but very frequent contractions (al and del) and a special rule for feminine words that begin with a stressed a- sound.

Structure: Definite: el / la / los / las • Indefinite: un / una / unos / unas

Definite articles — 'the'

Use these for something specific or already known, and also for nouns used in a general sense (which English often leaves bare).

el — masculine singular: el coche (the car)
la — feminine singular: la silla (the chair)
los — masculine plural: los coches (the cars)
las — feminine plural: las sillas (the chairs)

El coche de mi padre es azul. My father's car is blue. specific car → el
Me gustan los gatos. I like cats. general statement: Spanish keeps the article (los) where English drops it

Indefinite articles — 'a / an / some'

Use these for something new or non-specific. In the plural they mean 'some' or 'a few'.

un — masculine singular: un libro (a book)
una — feminine singular: una casa (a house)
unos — masculine plural: unos libros (some books)
unas — feminine plural: unas casas (some houses)

Quiero un café, por favor. I want a coffee, please. café → masculine → un
Hay unas personas en la puerta. There are some people at the door. unas = a few (feminine plural)

The two contractions: al and del

When the masculine 'el' follows the prepositions a (to) or de (of/from), the two words merge into one. This is obligatory, not optional. Note it only happens with el — never with la, los, las.

a + el = al → Voy al cine. (I'm going to the cinema.)
de + el = del → La puerta del coche. (The door of the car.)
No contraction with the others: a la, a los, a las, de la, de los, de las

Vamos al parque y volvemos del trabajo tarde. We go to the park and come back from work late. a+el=al, de+el=del
Voy a la escuela. I go to the school. a + la does NOT contract

When Spanish omits the article

Sometimes Spanish drops the article where you might expect one — especially with professions and quantities.

Unmodified professions after ser: Soy profesor. (I am a teacher.) — no un
But add the article if you describe it: Soy un buen profesor.
After hay (there is/are) with plurals: Hay libros en la mesa.

Mi madre es médica. My mother is a doctor. profession with ser → no article
Es un médico excelente. He is an excellent doctor. described profession → article comes back

Feminine words starting with stressed a-

To avoid two a-sounds clashing, feminine singular nouns that begin with a stressed a- or ha- take el/un instead of la/una. The noun stays feminine, and the plural goes back to las/unas.

el agua (but: las aguas), el águila (the eagle), el hacha (the axe), un alma (a soul)
Adjectives stay feminine: el agua fría, mucha agua

El agua está fría pero las aguas del mar están calientes. The water is cold but the sea waters are warm. singular el agua, plural las aguas — always feminine

Common mistakes

✗ Voy a el cine. ✓ Voy al cine. a + el always contracts to al.
✗ Soy un profesor. ✓ Soy profesor. Drop the article with an unmodified profession after ser.
✗ el agua frío / la agua ✓ el agua fría el agua for sound, but the noun is feminine (fría).
✗ la problema / un problema... la mapa ✓ el problema, el mapa Match the article to the real gender, not just the ending.