The plural of a noun usually ends with -"s". For example, dog ("chien") becomes dogs ("chiens"). However, if a noun ends in -"au", -"eu", or -"ou", it can have -"x" at the end as a plural. For example, game ("jeu") becomes games ("jeux"). If a noun already ends with -"s", -"x", or -"z", it does not change in the plural.