Why do French adjectives change their ending? (e.g. actif/active)

Each French noun (an object word such as 'boy', 'table' or 'river') has a gender - they are either masculine or feminine. This may seem strange to a native English speaker as this is not a feature of our language, but it is very important for understanding French.

French adjectives change their ending depending on the gender and number of the noun they are describing. For example, 'actif' would describe a masculine noun (e.g. un garçon), 'active' would describe a feminine noun (e.g. une fille). If the adjective describes more than one object, then you need to add an 's' to the end of the adjective to create the plural form (e.g. les garçons actifs, les filles actives). If the adjective refers to a mixed group of masculine and feminine, then the masculine plural form is used ('les enfants actifs' if 'les enfants' includes boys and girls).

This is not as complicated as it sounds because there are certain patterns to the endings. For example, any adjective ending in '-if' for the masculine form will have the same feminine and plural endings as 'actif' ('-ive', '-ifs', '-ives').

If this is something you need help with, there are lots of patterns like this that I can teach you and help you practise.