singular (M) singular (F) plural (M or F)
my mon ma mes
your ton ta tes
his/her son sa ses
our notre notre nos
your (polite/pl) votre votre vos
their leur leur leurs
NOTE: don't forget, whether you use mon or ma, or son or sa has nothing to do with YOUR or the person you are talking about's gender. It has to do with the thing that is being owned.
EX. his grandmother - sa grand-mère, his brother - son frère, her brother - son frère