The indefinite article

A singular countable noun always has an article or another determiner with it.

The indefinite article a/an is used to talk about one particular person or thing when the listener does not know which one is meant, or when it does not matter which one.

·         She married an old man.

·         They have a big house in the city.

·         You had better consult a doctor.

·         I saw a hawker selling his wares on the street.

·         A man came and knocked at the door.

A/an is also used to talk about any one member of a class.

·         A teacher must have patience. (=any teacher)

·         A spider has eight legs. (=any spider)

·         A dog is faithful to its master.

·         A parrot can repeat what you say.

Cases where the indefinite article should not be used

With plural and uncountable nouns

The indefinite article cannot used before plural and uncountable nouns.

·         Apples are red.

·         Computers are expensive.

·         Time is money.

With possessives

We cannot use the indefinite article with possessives. We use double possessives instead.

·         He is a friend of mine. (NOT He is a my friend.)

With adjectives without nouns

We cannot use the indefinite article with an adjective alone (without a noun).

·         She is a beautiful girl.

·         She is beautiful. (NOT She is a beautiful.)