There are two things we know about the relative
usage of AN and A:
1. We use AN before a vowel
2. A word uses AN or uses A no matter where in the world you are, it never changes.
…well, no and no!
Here is a a quick 5 point novel guide to AN vs. A.
1. What exactly is the rule for using
AN?
The rule is
that you use AN before a vowel sound. So, even though, hour begins with a consonant it
possesses a vowel sound so we say an
hour.
2. What exactly is the rule for using A?
The rule is
that you use A before a consonant sound. So, even though, Eucalyptus begins with a vowel it
possesses a consonant sound so we say a
Eucalyptus tree.
3. Watch out for some troublesome
consonants like h and m
Though, a
hermit, he was always an honorable man.
I have a
Masters in Business Administration or all so know as an MBA
4. Watch out for some troublesome
consonants like o and u
You can use an
umbrella at a university.
It was an
open field in the 400 meters, a one lap race
5. Watch out for accents
AN and A are
driven by the consonant sound or the vowel sound and so an accent can
potentially change the use of AN and A. Rosemary is an erb in North America and a
herb in England (even Microsoft spell checker thinks it is an erb.)
