Nouns and adjectives: formation of the plural

Nouns and adjective follow similar rules.

1. Nouns and adjectives ending in -s, -x, or -z in the singular generally do not change in the plural:

heureux, heureux
le nez, les nez

2. The most common way to form the plural is by adding -s to the singular:

le livre, les livres
intéressant, intéressants

3. Words ending in -al generally take -aux in the plural:

le journal, les journaux
radical, radicaux
BUT: bal, bals; final, finals; festival, festivals

4. Many words ending in -u are followed by -x rather than -s:

genou, genoux
beau, beaux
nouveau, nouveaux
caillou, cailloux

5. Many compound words form irregular plurals.

le tire-bouchon, les tire-bouchon
un arc-en-ciel, des arcs-en-ciel

See also