Rules and Applications For the indefinite articles

1. A and AN is used to describe people and things :

1.1. EXAMPLE

1.2. A man, A table, An umbrella

2. An is used before words beginning with a vowel or h is not uttered

2.1. EXAMPLE

2.2. An orange, An envelope ,

3. A is used before words beginning with a consonant

3.1. EXAMPLE

3.2. A chair ,an Apple a wallet

4. We do not use a / an with names or nouns that are written in plural or are countless , because a / an means "one "