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 P8-a). For clarity, writers choose between concrete and abstract nouns (see W5-b). The distinction between count nouns and noncount nouns can be especially helpful to multilingual writers (see M2-a). Most nouns have singular and plural forms; collective nouns may be either singular or plural, depending on how they are used (see G1-f and G3-a). Possessive nouns require an apostrophe (see P4-a).