A or an before nouns

An should be used before countable nouns that talk about one person or thing, and begin with a vowel sound (a, e, i, o, u).

  • Do you want an apple or a banana?
    (Apple, a-pel – vowel sound. Banana, bah-nan-a. No vowel sound.)
  • I have an egg.
    (eh-g)
  • She is eating an ice-cream.
    (eye-scream)

The sound is important not the spelling.

  • She is an hour late.
    (h is silent – pronounced our. No vowel sound so no a nor an.)
  • An umbrella.
    (um-brell-a)
  • A university.
    (you-ni-ver-sity. Vowel sound so a.)

If a word is put between the article and the noun it will affect the use of either a or an.

Compare:

  • I have an egg.
    (eh-g – vowel sound)
  • I have a fried egg.
    (fr-eye-d – no vowel sound)