Superlative — Le superlatif
The superlative expresses the highest or lowest degree of a quality within a group — 'the most' or 'the least'. It is formed using the definite article (le/la/les/l') + plus or moins + adjective + de (of/in). The adjective and article must agree in gender and number with the noun.
Rules
Formation: le/la/les/l' + plus + adjective + de — means 'the most... of/in' (C'est la ville la plus intéressante de la région = It is the most interesting city in the region)
Formation: le/la/les/l' + moins + adjective + de — means 'the least... of/in'
The definite article (le/la/les) must agree with the noun being described
The adjective must also agree in gender and number with the noun
Irregular superlative for 'bon': le meilleur / la meilleure / les meilleurs / les meilleures (the best)
Irregular superlative for 'mauvais': le pire / la pire / les pires (the worst)
The preposition 'de' follows the superlative to indicate the group (de la classe, du monde, de la région)
Examples
C'est la ville la plus intéressante de la région. — It is the most interesting city in the region.
Il est le plus grand de la classe. — He is the tallest in the class.
C'est le meilleur restaurant de la ville. — It is the best restaurant in the city.
Elle est la moins sportive de la famille. — She is the least sporty in the family.
Ce sont les pires résultats de l'année. — These are the worst results of the year.
Paris est la plus belle ville du monde. — Paris is the most beautiful city in the world.