Articles A, AN
by Gerson Guzman
1. The article AN is used before singular, countable nouns which begin with vowel sounds.
1.1. He is an actor.
1.2. She didn't get an invitation.
1.3. I saw an eagle at the zoo.
2. If there is an adjective or an adverb-adjective combination before the noun, A(AN) should agree with the first sound in the adjective or the adverb-adjective combination.
2.1. He is an excellent teacher.
2.2. I saw a really beautiful eagle at the zoo.
3. The article A is used before singular, countable nouns which begin with consonant sounds.
3.1. He is a teacher.
3.2. She doesn't own a car.
3.3. I saw a bear at the zoo.
4. Remember that A(AN) means "one" or "a single". You cannot use A(AN) with plural nouns.
4.1. I saw a bears in Yellowstone National Park. Not Correct
4.2. I saw bears in Yellowstone National Park. Correct