Learning english is as easy as ABC. Here are some simple rules to follow.
1. 'An' is used before vowels. (Vowels are the letters: a, e, i , o, u.)
2. 'A' is used before consonants. (Consonants are all the letters which are not vowels. Easy right!)
EXAMPLES:
an apple
an egg
an umbrella
an orange
a box
a cat
a dog
a puppy
a noise
a voice
a youth
HOWEVER, THERE ARE EXCEPTIONS:
a useful thing
a one-eyed lamb
a European
a uniform
a unanimous voice
*the form 'A' is used before a vowel that has a sound of a long "yoo", or "wun"*
an hour
an honest man
an x-ray examination
*the from 'An' is used before a consonant that is not sounded, or has a sound of vowel*
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