A proper noun is a noun directly associated with an entity and primarily used to refer to that entity, such as London, Jupiter, Sharon, or Microsoft, as distinguished from a common noun, which is a noun directly associated with a class of entities and primarily used to refer to instances of a specific class.
A proper noun is a specific (i.e., not generic) name for a particular person, place, or thing. Proper nouns are always capitalized in English, no matter where they fall in a sentence. Because they endow nouns with a specific name, they are also sometimes called proper names.
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