Definition of a indefinite article from the Oxford Advanced Learner's Dictionary

      

    a

     indefinite article
    indefinite article
    BrE BrE//ə//
     
    ; NAmE NAmE//ə//
     
    ; BrE strong form BrE////
     
    ; NAmE strong form NAmE////
     
    (also an
    BrE BrE//ən//
     
    ; NAmE NAmE//ən//
     
    ; BrE strong form BrE//æn//
     
    ; NAmE strong form NAmE//æn//
     
    )
    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.
     
    jump to other results
  1. 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. 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. 3  any; every A lion is a dangerous animal.
  4. 4  used to show that somebody/something 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. 5used in front of two nouns that are seen as a single unit a knife and fork
  6. 6used instead of one before some numbers A thousand people were there.
  7. 7used when talking about prices, quantities and rates synonym per They cost 50p a kilo. I can type 50 words a minute. He was driving at 50 miles an hour.
  8. 8a person like somebody She's a little Hitler.
  9. 9used before somebody’s name to show that the speaker does not know the person There's a Mrs Green to see you.
  10. 10used before the names of days of the week to talk about one particular day She died on a Tuesday.
  11. Word Origin Middle English: weak form of Old English ān ‘one’.
See the Oxford Advanced American Dictionary entry: a