Using Articles:
A, An, or The 

Strategy for Mastery Proper Nouns
Five Sources of Definiteness A vs An

Choosing between "A" and "AN"

A and An are used with common nouns only which are countable and singular.

"A" is used before words that begin with consonant sounds ("a rock," "a large park")

"An" is used before vowel sounds ("an interesting subject,, "an apple").


Note on usage

Learning hint

Strategy for success