The adverbial superlative is used to express the highest or lowest degree of an action or manner. It modifies the verb and not the noun, which distinguishes it from the adjective's superlative. To situate this formation in the system of adverbs, see also [Formation of Adverbs] and [Comparative Adverbs].

The most common form pairs the invariable article le with plus or moins followed by an adverb. This structure is generally placed after the verb it specifies. When one wants to specify the entire comparison, one adds de + group, for example de tous or de la classe.

IdéeIdea.	ExempleExample.
Le superlatif relatif de l’adverbe emploie le plus pour marquer le degré supérieur.The relative superlative of the adverb uses le plus to mark the higher degree.	Il court le plus viteHe runs the fastest.
Le superlatif relatif de l’adverbe emploie le moins pour marquer le degré inférieur.The relative superlative of the adverb uses le moins to mark the lower degree.	Elle parle le moins fortShe speaks the least loudly.
L’article le reste invariable devant l’adverbe.The article le remains invariable in front of the adverb.	Ils travaillent le plus efficacementThey work most efficiently.
Le groupe de plus précise l’ensemble comparé.The 'plus' group specifies the set being compared.	Elle chante le mieux de tousShe sings the best of all.

The most common placement of an adverb generally follows the verb. In certain literary or poetic contexts, the order may be more flexible, but common usage favors the position after the verb. For habits of adverb order, one can consult [Place of Adverbs] and [Adverbs of Manner].

IdéeIdea.	ExempleExample.
Le superlatif adverbial suit généralement le verbe.The adverbial superlative usually follows the verb.	Elle explique le plus clairementHe explains the most clearly.
Le complément de comparaison peut suivre la structure.The complement of comparison can follow the structure.	Il répond le plus calmement de la classeHe answers most calmly in the class.
Le registre littéraire peut assouplir l’ordre habituel.The literary register can soften the usual order.	Poétiquement, il avance le plus lentementPoetically, he moves the slowest.

Some adverbs have irregular or more natural superlative forms than the regular periphrase. 'Bien' becomes 'le mieux' and 'peu' becomes 'le moins', while spoken forms can sometimes use 'plus mal' or 'pis' for a familiar value. When the adverb does not have a usual synthetic form, the periphrase remains the normal solution.

IdéeIdea.	ExempleExample.
Bien devient le mieux au superlatif.'Bien' becomes 'le mieux' in the superlative.	Elle chante le mieuxShe sings the best.
Peu devient le moins au superlatif.'Peu' becomes 'le moins' in the superlative.	Il parle le moinsHe speaks the least.
Pis est une forme familière de plus mal.'Pis' is a familiar form of 'plus mal'.	Il conduit pis en hiverHe drives worse in winter.
La périphrase sert quand aucune forme synthétique ne s’impose.The periphrase is used when no synthetic form is required.	Elle travaille le plus rapidement possibleShe works as quickly as possible.

The relative adverbial superlative compares an action to a group, whereas the absolute superlative emphasizes intensity without explicit comparison. For the absolute, intensifiers like très or extrêmement are placed in front of the adverb. This distinction also helps to differentiate the adverbial superlative from [Adverbs of Quantity].

IdéeIdea.	ExempleExample.
Le superlatif relatif établit une comparaison avec un groupe.The relative superlative establishes a comparison with a group.	Elle parle le plus clairement de tousShe speaks the most clearly of all.
Le superlatif absolu exprime une forte intensité sans comparaison.The absolute superlative expresses strong intensity without comparison.	Il répond très rapidementHe answers very quickly.
Extrêmement renforce davantage l’adverbe.Extremely strengthens the adverb even more.	Elle travaille extrêmement sérieusementShe works extremely seriously.

The choice between several forms often depends on the register. In everyday speech, one often prefers the fastest or the clearest, while the formal register favors more rapidly or more clearly. Style differences are also found in [Adverbs of Manner], where precision and nuance guide the formulation.

RégionRegion.	Terme ou expressionTerm or expression.	Définition régionaleRegional definition.	ExempleExample.
CourantCommon.	le plus viteThe fastest.	Expression fréquente à l’oral pour indiquer la vitesse maximale dans un groupe.A common spoken expression to indicate the highest speed within a group.	Il finit le plus vite quand il est presséHe finishes the fastest when he is in a hurry.
SoutenuFormal.	le plus rapidementThe most rapidly.	Expression plus formelle qui convient mieux à l’écrit soigné.A more formal expression that is better suited to polished writing.	Elle répond le plus rapidement possibleShe answers as quickly as possible.
FamilierColloquial.	plus malWorse.	Tour oral fréquent pour exprimer une manière moins bonne ou dégradée.Common spoken expression to express a worse or degraded manner.	Il joue plus mal quand il fatigueHe plays worse when he is tired.