Grammatical gender is a system of noun classification. Many languages, including Spanish and French, have masculine and feminine categories for all nouns, whether people, animals, or objects. Other languages, like German and Romanian, have a third gender: neuter. The gender of a noun affects other parts of speech, including articles, adjectives, and pronouns.
English has a few natural gender nouns that denote specifically male or female people or animals, such as man, woman, actor, actress, bull, and cow. It also has many "common gender nouns" which can refer to people of either gender, such as child, parent, student, and cousin. Non-animate English nouns have no gender, in contrast to Spanish and many other languages.