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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.
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.)
Sections in this article
Introduction to Articles
The Definite Article
Cases where the definite article should not be used
The Indefinite Article
Cases where articles should not be used
What to use - A/an or the
The difference between some/any and no article
Common expressions without articles
Articles: special rules and exceptions