A noun is the name of a person, place, thing, or concept.

Nouns sometimes function as adjectives modifying other nouns. Because of their dual roles, nouns used in this manner may be called noun/adjectives.

Nouns are classified in a variety of ways. Proper nouns are capitalized, but common nouns are not (see 45a). For clarity, writers choose between concrete and abstract nouns (see 18b). The distinction between count nouns and noncount nouns can be especially helpful to multilingual writers (see 29a). Most nouns have singular and plural forms; collective nouns may be either singular or plural, depending on how they are used (see 21f and 22b). Possessive nouns require an apostrophe (see 36a).