Question

what is the rule for article an

Answer 1

the rule is an is used in front of vowels a e i o u

Answer 2

1. An is used before every vowel.
ex:- an apple, an egg

2. An is used before the word which starts which consonant but it sounds that it is starting with vowel.
ex:- an honest person etc.

3. An is used before abbreviations.
ex:-an ias,an hiv patient etc.

hope this helps ^_^