Grammatical gender is a system of noun classification found in many languages, where nouns are assigned to different categories such as masculine, feminine, or neuter. This classification can affect the form of other words in the sentence, such as adjectives and pronouns, as well as the agreement of verbs. Grammatical gender is not necessarily related to the biological gender of the noun, and in some languages, nouns can have gender categories that do not align with notions of male and female. Studies in this area aim to understand the patterns and rules of gender assignment in different languages, as well as the cognitive and communicative implications of grammatical gender systems.