The main semantic function of the article is that of correlation of a no­tion with the world described in a text (or with the situation of communica­tion). Obviously the speaker’s choice of the article is situation-dependent. Specifically, the definite article the and the indefinite article a(n) have three meaningful characterizations of the nounal referent: one rendered by the definite article, one rendered by the indefinite article, and one rendered by the absence of the article.

The definite article individualizes or identifies the referent of the noun: the use of the definite article shows that the object referred to is known to the hearer and is taken in its concrete, individual quality. This observation is con­firmed by a substitution test: the definite article may be replaced by a demon­strative determiner this, that, these, those without any change in the general implication of the construction. Though the semantic difference between a determiner and an article admits of no argument, yet the replacement of the words as a special diagnostic procedure is quite permissible. The identifica­tion takes place when the referent is mentioned for the second time:

At the same time he caught the sound of children’s voices and looked round to see, thirty yards away, a small boy and a girl and a blonde tall young woman in a plain white swimsuit and carrying a blue wrap¹?coming across the shore. Even at that distance he thought the girl  had an allof aris­tocratic, even supercilious air. (Bates)

The definite article is used with nouns that are modified by attributive constructions.

But what happened to the people I knew in college? Or in high school? Amy Darrow – the girl who had her engagement party the night I met Joe, remember? (Tyler)

The definite article may also be used with the noun whose referent is mentioned for the first time but is so much common for a given situation that it does not require any special introduction:

Mary and Bob sat in silence, the engine still running while Bob banged impatiently with one hand on the steering-wheel. (King)

The definite noun is used with nouns that denote unique referents: the earth, the sun, the moon, the East, the world, the universe.

In contrast to the identifying meaning of the definite article, the indefi­nite article is associated with a classifying meaning. The indefinite article may point out a concrete referent but in doing so it does not single out this referent among similar referents of the class and it does not identify the ref­erent as already known. As a result, it is used to introduce a new element in the sentence., Since a new element is always the most prominent and attracts attention, a noun with the indefinite article frequently becomes the center of the utterance and as such is marked by strong stress.

“Hello-o-o!” Biddy called, and the clatter of catering trays followed the slam of the door. Then Binstock arrived with the flowers, and a woman phoned to arrange an office cocktail party, and the plasterer showed up to mend the hole in the dining-room ceiling. (Tyler)

The indefinite article, as different from the definite article, is commonly interpreted as referring the object denoted by the noun to a certain class of similar objects; in other words, the indefinite article may express a classify­ing generalization of the nounal referent. Cf.:

“I’m thinking of taking a trip. ” she told Zeb on the phone. (Tyler)

She threw away an entire sheet of postage stamps, three-cent postage stamps. (Tyler)

It should be pointed out that both the definite and the indefinite articles express generalization, when used with a noun in singular: The (a) whale is a mammal. Meanwhile, the indefinite article is preferable in sentences describing some situational qualities: A whale is dangerous when defending its whale-calf.

As to their relation with the various classes of nouns, depending on the situation, both the definite and the indefinite articles are used without any particular restrictions with common nouns denoting concrete objects or liv­ing beings, e.i. countable nouns: The book was returned. The books were re-turned. The indefinite article is not used with nouns in plural, since it retains its vestigial meaning “one”.

The definite article is, in its turn, absent with abstract and material nouns. However, it is used with abstract and material nouns if they are modified by attributes:

At the sight, and at the relief it brought him, he realized how anxious he had been. (Hartley)

The policeman, if such he was, seemed to be moving towards him and Wal­ter suddenly became alive to the importance of small distances… (Hartley)

The indefinite article may sometimes occur with abstract nouns denot­ing feelings. In these cases, the article implies that the noun denotes some particular kind or new manifestation of the feeling:

Semantic functions of the definite and the indefinite articles – Part 2