Interestingly my language has both genders and (reduced but present) animate-inanimate distinction. It also used to have singular, plural and "double" declination. As far as I understand this all was originally "invented" in proto-indo-european. Man, PIE was wild.
My language has male/female/neuter in singular and male-person/everything-else in plural (e.g. singular dog is male and declines like boy, but plural dogs is non-male-person and declines like girls).
It used to have dual number, now it's just singular and plural. There are, however, exactly three words that use the dual number rules for its plural, even for N>2: hands, eyes and ears.
