/ ə; NAmE ; strong form eɪ/ (also an / ən; NAmE ; strong form æn/) indefinite article
HELP NOTE : The form a is used before consonant sounds and the form an before vowel sounds. When saying abbreviations like 'FM' or 'UN', use a or an according to how the first letter is said. For example, F is a consonant, but begins with the sound / e / and so you say:
an FM radio
. U is a vowel but begins with / j / and so you say:
a UN declaration
.
1.
used before countable or singular nouns referring to people or things that have not already been mentioned :
a man / horse / unit
an aunt / egg / hour / x-ray
I can only carry two at a time.
There's a visitor for you.
She's a friend of my father's (= one of my father's friends) .
2.
used before uncountable nouns when these have an adjective in front of them, or phrase following them :
a good knowledge of French
a sadness that won't go away
3.
any; every :
A lion is a dangerous animal.
4.
used to show that sb/sth is a member of a group or profession :
Their new car's a BMW.
She's a Buddhist.
He's a teacher.
Is that a Monet (= a painting by Monet) ?
5.
used in front of two nouns that are seen as a single unit :
a knife and fork
6.
used instead of one before some numbers :
A thousand people were there.
7.
used when talking about prices, quantities and rates
SYN per :
They cost 50p a kilo.
I can type 50 words a minute.
He was driving at 50 miles an hour.
8.
a person like sb :
She's a little Hitler.
9.
used before sb's name to show that the speaker does not know the person :
There's a Mrs Green to see you.
10.
used before the names of days of the week to talk about one particular day :
She died on a Tuesday.
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WORD ORIGIN
Middle English : weak form of Old English ān one .