Most nouns add a silent -s, so the plural is usually heard in the ARTICLE rather than the noun: le livre becomes les livres, and only les changes the sound. Words ending in -eau or -eu take -x instead, and ones already ending in -s or -x do not change.
Examples
- J'ai deux frères et trois soeurs.
- I have two brothers and three sisters.
- Les hôtels sont complets.
- The hotels are full.
- Il y a trois bureaux ici.
- There are three offices here.
The mistake to avoid
Because the -s is silent, les is what a listener hears - drop it and the plural disappears entirely.
Where this fits in
Numbers, days, time, French A1: Count, talk about days and months, give the time, and handle numbers in real situations.