The Indefinite Article

1. The indefinite article

The indefinite articles are: a and an.

We use a in front of a consonant sound

a book, a table, a hotel, a moment,

a tall father, a blue car, a nice pie, a fire

We use an in front of a vowel sound

an apple, an hour, an architect, an animal,

an important decision, an efficient worker

The plural of a/an is zero or some/any

a cat – cats, some cats

a cinema – cinemas, some cinemas

2. The use of the indefinite article

when we mention something for the first time:	‘He’s just bought a house.’ ‘Wow. That’s fantastic.’
when we talk about one item of a group:	I’d like to buy a car.
with adjective + noun:	We saw a huge, black panther.
when talking about somebody’s job:	She is a high school teacher.
when talking about a kind/example of something:	We bottle a fine wine. (= a type of fine wine)
when talking about amounts:	a kilo of potatoes, a thousand litre of water
difference between a and one:	I’d like a slice of cake please. ‘ But: ‘I wanted only one slice, not two!’
when talking about frequency, price, distance (meaning per)	5 miles an hour, two pound a kilo, twice a week
When talking about illnesses:	I have a cold. I have a headache. I have a pain in my arm. Except: flue, blood pressure and plural diseases (measles, mumps)
With what and such when using singular, countable nouns:	What a nice day! Such a lovely dog.