In linguistics, a grammatical gender system is a specific form of a noun class system, where nouns are assigned to gender categories that are often not related to the real-world qualities of the entities denoted by those nouns. In languages with grammatical gender, most or all nouns inherently carry one value of the grammatical category called gender. The values present in a given language, of which there are usually two or three, are called the genders of that language. Determiners, adjectives, and pronouns also change their form depending on the noun to which they refer.
According to one estimate, gender is used in approximately half of the world's languages.