Qualificative Adjectives — Les adjectifs qualificatifs
Qualificative adjectives describe the qualities or characteristics of a noun. In French, most adjectives come after the noun (unlike English) and must agree in gender and number.
Rules
Most adjectives are placed after the noun (un livre intéressant = an interesting book)
Some common adjectives come before the noun: beau, bon, grand, gros, jeune, joli, long, mauvais, nouveau, petit, vieux
Add -e for feminine (petit → petite, grand → grande)
Add -s for masculine plural (petit → petits)
Add -es for feminine plural (petite → petites)
Some adjectives have irregular feminine forms (beau → belle, nouveau → nouvelle, vieux → vieille)
Examples
C'est une jolie maison. — It is a pretty house.
Il porte une chemise bleue. — He wears a blue shirt.
Elle a de longs cheveux noirs. — She has long black hair.
Ce sont de bons élèves. — They are good students.
La vieille dame est gentille. — The old lady is kind.
Il a un nouveau vélo. — He has a new bicycle.