I just bought a box of Mike and Ike candies. When I looked at the special offer emblazoned across the top of the front side of the box, something caught my eye. It said, "You could win instantly! $10 in music downloads or a MP3 player."

So what's wrong with that statement? Ignore the whole starting with a dollar amount thing -- that falls under the freer use of style for advertising.

What doesn't get a pass is "a MP3 player." It should be "an MP3 player." Here's the rule for that: Choosing between "a" or "an" isn't governed by the actual letter that follows it, but rather by the sound that letter makes. If it is a consonant sound, you use "a." If it's a vowel sound, you use "an."

So let's look at "MP3." While the letter "m" is a consonant, the name for the letter itself, "em," actually begins with a vowel sound -- "eh." So, just like we would say, for instance, "an emerald," we also say "an MP3 player."

For the same reason, we say "an hour" and not "a hour." The "h" isn't pronounced, so the first sound in the word is the vowel sound that "ou" makes.

By the way, the grammar faux pas on the Mike and Ike box doesn't sour me on the candy inside. I still love 'em.