The definite articles indicate that the noun is known, identifiable, or specific within the context. In Spanish, the, la, los and las agree in gender and number with the noun they accompany. They usually precede the noun and form an essential base of nominal determination, together with other types of determiners such as the Indefinite Articles.

The basic forms of the definite article clearly express gender and number. The choice depends on the noun they accompany and its agreement. In singular, el and la distinguish masculine and feminine; in plural, los and las maintain the same opposition.

IdeaIdea	EjemploExample
El acompaña a sustantivos masculinos singulares.The accompanies masculine singular nouns.	El libro está abierto.The book is open.
La acompaña a sustantivos femeninos singulares.The accompanies feminine singular nouns.	La silla es cómoda.The chair is comfortable.
Los acompaña a sustantivos masculinos plurales.The accompanies masculine plural nouns.	Los perros corren.Dogs run.
Las acompaña a sustantivos femeninos plurales.The accompanies feminine plural nouns.	Las mesas son nuevas.The tables are new.

The definite article agrees with the noun in gender and number, and that agreement remains even when the noun changes form by pluralization. This relationship also helps identify the gender of nouns that do not show a transparent ending. When the noun changes, the article changes with it.

IdeaIdea	EjemploExample
El artículo cambia a masculino singular cuando el sustantivo es masculino singular.The article changes to masculine singular when the noun is masculine singular.	El coche es rojo.The car is red.
La artículo cambia a femenino singular cuando el sustantivo es femenino singular.The article changes to feminine singular when the noun is feminine singular.	La vela está encendida.The candle is lit.
Los artículo cambia a masculino plural cuando el sustantivo es masculino plural.The article changes to masculine plural when the noun is masculine plural.	Los cuadernos están sobre la mesa.The notebooks are on the table.
Las artículo cambia a femenino plural cuando el sustantivo es femenino plural.The article changes to feminine plural when the noun is feminine plural.	Las paredes son blancas.The walls are white.

Definite articles are used with nouns that are already identified, unique in their context, or understood as groups known. They also appear with unique elements like the sun and the moon, with days and seasons like Monday and spring, and with generalized categories like Dogs bark. In many cases, the article turns a noun into a reference shared by speakers and listeners.

IdeaIdea	EjemploExample
El artículo aparece con sustantivos únicos.The article appears with unique nouns.	El sol brilla.The sun shines.
El artículo aparece con días y estaciones.The article appears with days and seasons.	El lunes empieza temprano.Monday starts early.
Los artículo puede generalizar una categoría.The article can generalize a category.	Los perros ladran.Dogs bark.
El artículo puede introducir sustantivos abstractos y disciplinas.The article can precede abstract nouns and disciplines.	La historia explica el pasado.History explains the past.

The definite article is obligatory with many parts of the body and garments when the noun forms part of a natural construction and explicit possession is not expressed. It is also used with abstract nouns and with names of disciplines, such as history or mathematics, because they function as bounded concepts. Its normal placement is before the noun, and it is not usually separated from it except in very marked or specialized contexts.

IdeaIdea	EjemploExample
El artículo suele acompañar partes del cuerpo.The article usually accompanies parts of the body.	Me lavé las manos.I washed my hands.
El artículo suele acompañar prendas.The article usually accompanies garments.	Perdí la chaqueta.I lost the jacket.
El artículo acompaña disciplinas académicas.The article accompanies academic disciplines.	Las matemáticas requieren práctica.Mathematics requires practice.
El artículo precede al sustantivo.The article precedes the noun.	La casa está cerca.The house is nearby.

The combinations a + the and de + the fuse into al and del. These contractions are obligatory in standard use and appear when the masculine singular article comes after a preposition. They are not formed with the other articles, so contraction depends on the exact sequence.

IdeaIdea	EjemploExample
A más el se contrae en al.A + the fuses into al.	Voy al cine.I go to the cinema.
De más el se contrae en del.De + the fuses into del.	Vengo del parque.I come from the park.
La contracción solo ocurre con el singular masculino.The contraction only occurs with the singular masculine.	Salgo del edificio.I leave the building.
Otras combinaciones no forman contracción.Other combinations do not form contractions.	Entro a la tienda.I enter the store.

Some feminine nouns that begin with a stressed /a/ use the masculine article el in singular to avoid repeating sounds, though they retain their feminine gender. In plural they regain the normal feminine form, such as aguas or almas. In formal contexts, surnames may carry a prefixed article in expressions like el señor García, and in some areas it also appears with proper names in colloquial use.

IdeaIdea	EjemploExample
Un sustantivo femenino con a tónica puede usar el en singular.A feminine noun starting with a stressed a can use the el in singular.	El agua está fría.The water is cold.
En plural, ese sustantivo vuelve a las.In plural, that noun returns to the feminine form.	Las aguas están tranquilas.The waters are calm.
Algunos apellidos admiten artículo en registros formales.Some surnames accept an article in formal registers.	El señor García llegó.Mr. García arrived.
En ciertos contextos coloquiales, algunos nombres propios llevan artículo.In certain colloquial contexts, some proper names carry an article.	La María vive cerca.María lives nearby.

The definite article can be omitted in vocatives, lists, and very condensed styles, as sometimes happens in the press or recipes. In general language, however, the presence of the article remains the norm when the noun needs delimitation. To contrast this behavior with other determiners, it is worth reviewing Omission of the Article.

IdeaIdea	EjemploExample
En vocativos, el artículo suele omitirse.In vocatives, the article is often omitted.	María, ven aquí.María, come here.
En listados, el artículo puede omitirse.In lists, the article can be omitted.	Pan, leche, fruta.Bread, milk, fruit.
En prensa o recetas, el estilo puede ser más breve.In journalism or recipes, the style can be shorter.	Titular breve, texto directo.Short headline, direct text.
Cuando el sustantivo necesita delimitación, el artículo se mantiene.When the noun needs delimitation, the article is kept.	La caja está cerrada.The box is closed.

Definite articles position the noun as known, unique, or shared, and their form changes according to gender and number. They can also express generalization, appear with certain special nouns, contract with specific prepositions, and vary by register or region. Mastery requires attending to agreement, to placement before the noun, and to the contexts in which the article is omitted or kept.