Demonstrative adjectives point to a noun and place it according to the distance of the speaker in space or in time. They always accompany the noun and agree with it in gender and number, as with other Adjectives and with the Adjectival Concord. Their main function is to identify which of several referents is to be highlighted.

The basic forms distinguish proximity, middle distance, and remoteness. This and this express closeness; that and that express intermediate distance; that one and that one express remoteness, and their plurals mark the same opposition. The gender and number change to agree with the noun, just as in the Position of the Adjective and in other determiners that accompany it.

IdeaIdea	EjemploExample
Este cambia a esta, estos y estas según el sustantivo.This changes to this, these and these depending on the noun.	este librothis book
Ese cambia a esa, esos y esas para distancia intermedia.That changes to that, those and those for intermediate distance.	esa casathat house
Aquel cambia a aquella, aquellos y aquellas para mayor lejanía.That one changes to that one, those and those for greater distance.	aquellos díasthose days

This typically refers to proximity, that to the intermediate distance, and that to remoteness, both in space and time. In many varieties, that can cover a near or intermediate area depending on the region, so distance perception is not always identical across the Spanish-speaking world. The choice depends on the contrast the speaker wants to establish between the referents.

IdeaIdea	EjemploExample
Este marca proximidad inmediata.This marks immediate proximity.	esta mesathis table
Ese marca una distancia intermedia.That marks an intermediate distance.	esos momentosthose moments
Aquel marca lejanía espacial o temporal.That marks spatial or temporal remoteness.	aquella épocathat era

These adjectives usually go before the noun they accompany, as part of normal nominal syntax. In poetic, literary or colloquial registers, the post-nominal position can appear exceptionally, but it is not the general rule. When they precede the noun, they maintain their demonstrative value and help to fix the referent with precision.

IdeaIdea	EjemploExample
La posición habitual es antes del sustantivo.The usual position is before the noun.	esa casathat house
La posición posnominal es excepcional.The post-nominal position is exceptional.	una casa esaa house that
El demostrativo sigue identificando al sustantivo.The demonstrative continues to identify the noun.	este cochethis car

This, that and that (aquello) are neuter forms that do not accompany an explicit noun. They are used to point to ideas, facts, situations, or actions already known by context. Their value is more abstract than that of masculine and feminine forms, so they work well when the referent is not named directly.

IdeaIdea	EjemploExample
Esto señala algo cercano en el discurso.This points to something close in the discourse.	esto importathis matters
Eso retoma una idea ya mencionada.That recalls an idea already mentioned.	eso bastathat suffices
Aquello alude a algo lejano o más difuso.That (aquello) alludes to something distant or more diffuse.	aquello ocurrióthat occurred

When the demonstrative accompanies a noun, it acts as a demonstrative adjective; when it substitutes it, it functions as a demonstrative pronoun. In traditional reading, forms with a tilde such as éste or aquél appeared, but the current RAE rule does not recommend it for demonstratives. This distinction is the basis of Demonstrative Pronouns and also appears in This, That, That.

IdeaIdea	EjemploExample
El adjetivo demostrativo acompaña al sustantivo.The demonstrative adjective accompanies the noun.	este cuadernothis notebook
El pronombre demostrativo sustituye al sustantivo.The demonstrative pronoun substitutes the noun.	este es míothis one is mine
La tilde en estas formas ya no se recomienda.The tilde on these forms is no longer recommended.	este casothis case

Demonstratives also serve to oppose referents and mark contrast, especially when two nearby options are presented in discourse. The structure this X, not that Y reinforces the choice of one element over another. It is also common in combinations such as this type of, this kind of, or these days of, where the demonstrative organizes the noun and the complement.

IdeaIdea	EjemploExample
El demostrativo puede crear contraste entre dos referentes.The demonstrative can create contrast between two referents.	este libro, no esethis book, not that
La secuencia este más sustantivo más de más complemento es frecuente.The sequence this plus noun plus of plus complement is frequent.	esta clase de tareathis kind of task
El contraste ayuda a precisar la elección del hablante.The contrast helps to specify the speaker's choice.	aquellos planes de veranothose summer plans

The demonstrative adjectives signal a noun, agree with it, and locate it by closeness, middle distance or remoteness. Their usual position is before the noun, although exceptional uses can appear in marked styles. When used without a noun, they pass to neuter forms, and when they replace the name, they belong to the system of demonstrative pronouns.