The article is a structural part of speech used with nouns. There are two articles in Modern English: the indefinite article and the definite article.

The definite article has one graphic form the.

The definite article has developed from the Old English demonstrative pronoun se and in some cases it has preserved this demonstrative meaning in Modern English.

The use of the definite article shows that a particular object is meant.

The indefinite article has the forms a and an. The form a is used before words beginning with a consonant sound (a book, a pen, a student). The form an is used before words beginning with a vowel sound (an opera, an apple, an hour).

The indefinite article has developed from the Old English numeral an (one), and as a result of its origin it is used only with nouns in the singular.

The use of the indefinite article implies that the object is presented as belonging to a class.

The absence of articles with class nouns in the plural, with abstract nouns and nouns of material has grammatical significance: it shows that the nouns are used in a general sense.