Why is the masculine and feminine words in french?

Answer 1

You mean what are they......

for one guy you say Il

for one girl you say Elle

for a group for girls you say Elles

for a group of girls with only one or more guys in it you would say Ils

for just a group of guys you would say Ils

For a group of guys with one girl you would still say Ils

Answer 2

French has grammatical gender, where nouns are either masculine or feminine. This distinction dates back to Latin and has been carried over into French. The gender of nouns in French can sometimes seem arbitrary and does not always correspond to biological gender.