Proper adjective

In English orthography, the term proper adjective is sometimes applied to adjectives that take initial capital letters, and the term common adjective to those that do not. These terms are used informally only; they are not used by grammarians or linguists. For example, a person from Boston is Bostonian. Bostonian is a proper adjective.

The term "proper noun" denotes a noun that, grammatically speaking, identifies a specific unique entity; for example, England is a proper noun, because it is a name for a specific country, whereas dog is not a proper noun — it is a "common noun" — because it is a term referring to any one member of a group of animals.

In English orthography, most proper nouns are capitalized, while most common nouns are not. As a result, the term "proper noun" has come to mean, in lay usage, "a noun that is capitalized", and "common noun" to mean "a noun that is not capitalized". Furthermore, English adjectives that derive from proper nouns are usually capitalized. Because of this, the terms "proper adjective" and "common adjective" have come to be used, with meanings analogous to the lay meanings of "proper noun" and "common noun". Proper adjectives are just capitalized adjectives.

In general, an adjective is capitalized if its meaning is "pertaining to X", where X is some specific person, place, language, or organized group. Most capitalized adjectives are derived from proper nouns; for example, the proper adjective American is derived from the proper noun America.

Sometimes, an adjective is capitalized because it designates an ethnic group with a shared culture, heritage, or ancestry. This usage asserts the existence of a unified group with common goals. For example, in Canadian government documents, Native and Aboriginal are capitalized.

An adjective can lose its capitalization when it takes on new meanings, such as chauvinistic. In addition, over time, an adjective can lose its capitalization by convention, generally when the word has overshadowed its original reference, such as gargantuan, quixotic, titanic, or roman in the term roman numerals.

An adverb formed from a capitalized adjective is itself capitalized. For example:

Verbs such as Canadianize are written with a capital letter, although not generally described as "proper verbs".

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