A term used in the grammatical classification of words, referring to a subclass of determiners which displays a primary role in differentiating the uses of nouns, e.g. the/a in English. Many languages have no article system (e.g. Russian). Of those which do, a distinction is usually made into definite and indefinite (or non-definite) types, partly on semantic and partly on grammatical grounds. Articles may appear before the noun (as in English), or after (as in Swedish).