why do nouns have gender in some languages
Grammatical gender The division into genders usually correlates to some degree, at least for a certain set of nouns (such as those denoting humans), with some property or properties of the things that particular nouns denote. Such properties include animacy or inanimacy, "humanness" or non-humanness, and biological sex.
Gender symbol The two standard sex symbols are the Mars symbol ♂ (often considered to represent a shield and spear) for male and Venus symbol ♀ (often considered to represent a bronze mirror with a handle) for female, derived from astrological symbols, denoting the classical planets Mars and Venus, respectively. They were first used to denote the effective sex of plants (i.e. sex of individual in a given crossbreed, since most plants are hermaphroditic) by Carl Linnaeus in 1751.[2]