Interlingua
Interlingua is an auxiliary language that was developed to have a widely international vocabulary and a very simple grammar. In Interlingua, nouns have no gender except to reflect natural sex. For example, the words homine (man) and femina (woman) are masculine and feminine, respectively, but persona (person) has no gender. Adjectives are invariable and so never have to agree in gender with the nouns they modify. There is a separate nongender pronoun (illo, "it") and the possessive pronoun su ("his", "her" or "its") is gender-neutral.
Nouns such as professor and conductor denote both men and women, but specifically feminine forms such as professora conductora have been used occasionally over time. Interlingua has largely escaped charges of sexism, perhaps because the language changes easily as social values change.
Read more about this topic: Gender-neutrality In Languages With Grammatical Gender, International Auxiliary Languages