§ 2. The Article and The Pronoun

Although both articles and pronouns, mainly de­monstrative and indefinite ones, determine nouns, they do so in a different way. First, the article determination of nouns is obligatory for the article is indispensable to signal the lexical meaning of a noun in terms of the main lexical oppositions: proper/common, abstract/concrete, coun­table/uncountable, animate/inanimate, human/non-hu­man. Second, whereas the function of the article is to specify nouns in the most general way, the demonstrative pronouns this/these, that/those and the in­definite pronouns some, any are used to define persons, things or notions denoted by nouns in relation to other persons, things or notions, their function being to present a noun in a more detailed way, with a higher degree of certainty. (E.g. A man called in while you were out. Not a woman. — Some man/some men called in while you were out. A man/men strange to me. Have an apple. Not an orange.— Have any apple you like. Every apple, no matter which one. Will you give me the pen? (Which is mentioned and understood by both speakers) — Will you give me this pen? (The one I am pointing to).)

Note that the use of the demonstrative pronouns is arbitrary though in most cases the definite article is more idiomatic. The use of the indefinite pronouns is arbitrary in the case they are to define countables both in the singular and plural. Their use may be obligatory if they are referred to uncountable nouns and countables in the plural. (E.g. There is some butter in the fridge. There isn't any jam in the cupboard. Have you got any money? (uncountables) There are some books on the shelf. There aren’t any nails in the box.)

§ 3. The use of the Indefinite Article

The indefinite article whose function is that of classification is used to determine only countable nouns in the singular. They include: 1) proper and common nouns, 2) concrete and abstract nouns, 3) animate and inanimate nouns, 4) human and non-human nouns. Common nouns can be either concrete or abstract. Proper nouns are ba­sically concrete.

The individual discussion of animate/inanimate and human/nonhuman nouns in terms of article determina­tion is irrelevant for all of them are common and concrete.

The Indefinite article before common concrete nouns

Common concrete nouns include: 1) class nouns, 2) collective nouns, 3) nouns denoting materials. Note that common collective nouns like poultry, police, machinery, etc. and common concrete nouns denoting materials such as air, water, iron and so on are not used with the indefinite article for they are uncountable. Indefinite article before common concrete class nouns

The indefinite article is used in the following cases:

a) Before a common concrete class noun denoting a person or a thing, which is not already mentioned or known about, either with or without a descriptive attribute, usually after the verbs be or have. (E.g. He is a writer. He is a famous writer. Have you got a car? I have a new car. I have a pain in my leg. There is a book on the table).

b) In the meaning «any, every» before a noun denoting the called person or thing: (E.g. A gentleman would never act like this. A parcel is bigger than a packet).

c) Before nouns denoting periods of time: three times a day, twice a week, once a month, etc.

d) In the meaning «one» before nouns of quantity and substantivized numerals: (E.g. a dozen eggs, a thousand pounds, a hundred times.)

e) Before the first noun of a pair that seems a single whole. (E.g. a cup and saucer.)

f) Before uncountable nouns that in the context turn into countable meaning «a container or unit of»: (E.g. I'd like a coffee, please, (a cup/a mug of coffee).