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 indefinite articlehas 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 article is pronounced [q], [qn]; when stressed it is pronounced [eI], [xn].
The definite articlehas one graphic form the, which is pronounced in two ways: [DJ]before a vowel sound [DJ "xpl] and [Dq] before a consonant sound [Dq "pen].
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 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 indefinite article implies that the object is presented as belonging to a class.
The use of the definite article shows that a particular object is meant.
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.
With nouns in the plural some is often used. Some, as well as the absence of articles with class nouns in the plural, is the equivalent of the indefinite article in the singular. Some is used when the speaker wants to emphasize the idea of number. Some is also used with nouns of material if the idea of quantity is implied. Some has the meaning of ‘several’ with class nouns and ‘a little’ with nouns of material. Some is hardly ever translated into Russian.