The indefinite article is a or an. The form an is used before a word that starts with a vowel sound.
The indefinite article is used with singular countable nouns:
|a girl||a cat|
|an eight-year-old girl||an engineer|
- to refer to a person or a thing that you are mentioning for the first time in a conversation or a piece of writing.
- A man was seen driving away in a black car.
- to refer to a person or a thing which you do not want to be specific about.
- I stopped off at a shop to buy a newspaper.
- You go past a petrol station on the left, and then you’ll see our house on the right.
- to refer to a person or a thing which you cannot be more specific about because there is not enough information.
- A man called to see you this afternoon.
- There was a telephone call for you a minute ago.
- An octopus is a sea creature with eight tentacles.
- when you refer to a person’s profession.
- Her father is a dentist and her mother is a teacher.
- to express a quantity, unless you wish to emphasize the number, when one must be used. The equivalent for plural nouns is some or no determiner at all. See Determiners.
It is the sound, not the spelling, that decides where an is used. For example, although unique begins with a vowel, the sound at the beginning resembles a y- sound.
- I want a needle and a thimble.
- Would you like a glass of wine?
- There is only one glass of wine left in the bottle.
- Guy has bought a skateboard.
- We’ve got three pairs of rollerblades and one skateboard.
|an idiot||an awful mistake|
|a unicorn||a unique experience|
There are a few words that begin with a silent h-, in front of which an should be used. They are: heir, heiress, honest, honour, hour.
- Very formal or old-fashioned speakers also use the an form with some words beginning with an h- that is not silent, especially historical and hotel.
|I waited an hour.|| |
|They joined a historical society.|| |
|They joined an historical society. ||(old-fashioned English)|
|They were staying at a hotel.|| |
|They were staying at an hotel.||(old-fashioned English)|