This came up in a Slashdot thread, and I thought I might as well post it here. Today's pet peeve: misuse of "an" before words starting with a voiced "h".
Most of us understand that when a noun starts with a vowel sound, you use "an" before it: "an apple". And most of us get that this includes words that start with a silent consonant: "an hour".
There are a few words, like "homage", that can be pronounced with the "h" either silent or not. It's silent in the preferred pronunciation, so "an homage", just like "an hour"; but if you're using some dialect where the "h" is pronounced, "a homage" would be correct. So either "a" or "an" could be okay there.
But there's a common misusage with some "h" words. I have a strong urge to punch people who say "an historic occasion" or "an hallucination". These are just wrong, unless you are a British aitch-dropper. ("An 'istoric occasion, guvnor!")
I'm not a big grammar stickler but this one grates on the ear. It does not leave me an happy camper.
The rule is simple: "an" before vowel sounds, "a" before consonants. The "n" in "an" is exactly there to hold vowels apart; if you don't have adjacent vowels (sounds, not symbols) in your phrase, it's redundant.
Because the rule is about sounds, not symbols, you also get cases where "a" rather "an" should be used before a word whose spelling starts with a vowel: "a union" or "a unicorn". If it helps, think of how you could spell these as "a (you)n-yin" or "a you-ni-corn".
And there there's acronyms: "a USB port", but "an MBA". ("A you-ess-bee port, an em-bee-ay".)
If we could all get this right, it would really cut down on my urges to punch people, and I'm sure there are others who feel the same way. So work for world peace: use the proper article. Thanks.