Do you use “an” when referring to a letter that has a vowel sound?

Question by James R: Do you use “an” when referring to a letter that has a vowel sound?
You know how we use “an” instead of “a” for words like ant, and hour, because they start with a vowel sound.
How about letters? Like do I say “a FAL” or “an FAL” because F has a vowel begining.

Best answer:

Answer by Bert
Well, that’s an historic question. Or is it a historic question? Oh, the dilemma.

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