The demonstrative adjective is used to designate a specific noun by pointing it out, by locating it in discourse, or by distinguishing it from other possible nouns. It agrees in gender and number with the noun it accompanies, as with the other French adjectives studied in Agreement of the adjective. It is placed directly in front of the noun and can also be inserted before a noun phrase developed by an attributive adjective, according to the rules of Position of the adjective.

Demonstrative adjectives have four main forms depending on gender, number and sometimes pronunciation. The choice of form depends on the noun they accompany, as with the other determiners studied in Indefinite Adjectives and Possessive Adjectives.

GenreGender.	FormeForm.	RègleRule.	ExempleExample.
Masculin singulierMasculine singular.	cethis.	S’emploie devant un nom masculin singulier qui commence par une consonne.Used before a masculine singular noun that begins with a consonant.	ce livrethis book.
Masculin singulierMasculine singular.	cetthis.	S’emploie devant un nom masculin singulier qui commence par une voyelle ou un h muet.Used before a masculine singular noun that begins with a vowel or a mute h.	cet amithis friend.
Féminin singulierFeminine singular.	cettethis.	S’emploie devant un nom féminin singulier.Used before a feminine singular noun.	cette maisonthis house.
PlurielPlural.	cesthese.	S’emploie devant un nom pluriel, quel que soit le genre.Used before a plural noun, regardless of gender.	ces enfantsthese children.

The demonstrative adjective always agrees with the noun it determines in gender and number. The sense of the sentence does not change the form chosen, because it is the noun that governs the agreement. This rule brings it closer to the other adjectives in Formation of the Adjective.

IdéeIdea.	ExempleExample.
Le masculin singulier emploie ce ou cet selon le son initial.The masculine singular uses ce or cet depending on the initial sound.	Ce voisin parle fort.This neighbor speaks loudly.
Le féminin singulier emploie cette.The feminine singular uses cette.	Cette fleur sent bon.This flower smells good.
Le pluriel emploie ces pour les deux genres.The plural uses ces for both genders.	Ces chaussures sont neuves.These shoes are new.

The demonstrative adjective always sits directly before the noun it determines. When the noun is developed by an attributive adjective, the whole phrase remains under the demonstrative's scope, as in Position of the adjective. The natural order is thus determinant, then a possible adjective, then the noun.

IdéeIdea.	ExempleExample.
Le démonstratif précède immédiatement le nom.The demonstrative precedes the noun immediately.	Ce carnet est ouvert.This notebook is open.
Le démonstratif peut précéder un adjectif épithète.The demonstrative may precede an attributive adjective.	Cette jolie robe brille.This pretty dress shines.
Le démonstratif reste devant le groupe nominal complet.The demonstrative remains in front of the complete noun phrase.	Ces très grands livres sont anciens.These very large books are old.

The forms with ci and là are used to specify proximity or distance. The form in ci refers to what is close, while the form in là refers to what is farther away. In speech, this opposition is often more marked, but written form preserves it to avoid any ambiguity.

IdéeIdea.	ExempleExample.
Ci marque la proximité.Ci marks proximity.	Cette chaise ci est libre.This chair here is free.
Là marque l’éloignement.There denotes distance.	Cette chaise là est cassée.That chair there is broken.
Ci et là s’ajoutent après le nom.Ci and là are added after the noun.	Cette fenêtre ci donne sur le jardin.This window here opens onto the garden.

The form cet appears before a vowel or a mute h to facilitate pronunciation. The initial sound, not the meaning of the word, decides here the form. Thus, we say cet été and cet ami, but we keep ce before an aspirated h as in ce héros.

IdéeIdea.	ExempleExample.
Cet s’emploie devant une voyelle.Cet is used before a vowel.	Cet arbre est vieux.This tree is old.
Cet s’emploie devant un h muet.Cet is used before a mute h.	Cet homme sourit.This man smiles.
Ce s’emploie devant un h aspiré.Ce is used before an aspirated h.	Ce héros arrive.This hero arrives.

The demonstrative adjective must not be confused with the demonstrative pronoun, which replaces the noun rather than accompanying it, as in Demonstrative pronouns. It should not be confused either with c’est, where c’est is the contracted form of the pronoun cela or ceci and not an adjective. In informal speech, one may sometimes hear simplified forms or omission of the demonstrative, but standard usage maintains the distinction.

IdéeIdea.	ExempleExample.
Ce accompagne un nom.This accompanies a noun.	Ce dossier est complet.This file is complete.
Celui remplace un nom.Celui replaces a noun.	Celui ci est complet.This one is complete.
C est appartient à c'est, et non à l'adjectif démonstratif.C belongs to c'est, and not to the demonstrative adjective.	C'est vrai.It's true.

Demonstrative adjectives form a small regular system based on gender, number and sometimes pronunciation. They are placed in front of the noun, agree with it, and take cet before a vowel or mute h, but ce before an aspirated h. Their value as a designation can be reinforced by ci or là to specify proximity or distance, which makes them essential for accurately identifying nouns in written and spoken discourse.