Most of the time, adding an "s" to the adjective ending is enough to make it plural. For example:

  • content becomes contents in the plural
  • contente becomes contentes in the plural

An adjective, ending with "x", remains the same in the plural. For example:

  • heureux remains heureux in the plural
  • but heureuse becomes heureuses in the plural

Some examples:

Gender Single Plural English
Male content contents happy
Feminine contente contentes
Masculine lent lents slow
Feminine lente lentes
Masculine gourmand gourmands fond of good food
Feminine gourmande gourmandes
Masculine déçu déçus disappointed
Feminine déçue déçues
Masculine amoureux amoureux in love
Feminine amoureuse amoureuses