Singular & Plural Adjectives

Adjective spellings also change according to whether you are describing one thing (singular) or more (plural). Usually we just add an -s:

e.g. ils sont grands - they are tall (masculine)
elles sont grandes - they are tall (feminine)

If the adjective ends in an -x or an -s, do not change the plural spelling:

e.g. le chateau est merveilleux - the castle is wonderful
le ciel est gris - the sky is grey

Adjectives ending in -al (masculine singular) change to -aux (masculine plural)
e.g. principal > principaux