article

an

The form of a used before a vowel sound.

She places an apple beside the sandwich in her lunchbox.

Etymology

The indefinite article developed from the word for “one.” It introduces a single, unspecified member of a class, retaining its fuller form before a vowel sound.

More examples

  • We waited for an hour before the doors opened.
  • He has an unusual solution to the problem.
  • The guide points out an old bridge beyond the trees.

Similar words

a
Used before a consonant sound rather than a vowel sound.