A/an use with acronyms

OK, I’m pretty embarrassed to be asking this but in the spirit of there are no stupid questions…
I got asked the other day about using a/an in front of acronyms and I found myself struggling to give a definite answer.

Now I know you would say an LCD screen, and an IBM representative. I feel this is because the L sound is

Use an in place of a when it precedes a vowel sound, not just a vowel. That means it’s “an honor” (the h is silent), but “a UFO” (because it’s pronounced yoo eff oh). This confuses people most often with acronyms and other abbreviations: some people think it’s wrong to use “an” in front of an abbreviation (like “MRI”) because “an” can only go before vowels. Poppycock: the sound is what matters. It’s “an MRI,” assuming you pronounce it “em ar eye.”

and this

[url=http://alt-usage-english.org/intro_d.shtml#Aoran]“A” is used before words beginning with consonants; “an”, before words beginning with vowels. This is determined by sound, not spelling (“a history”, “an hour”, “a unit”, “a European”, “a one”).

Formerly, “an” was usual before unaccented syllables beginning with “h” (“an historian”, “an hotel”); these are “now obsolescent” in British English (Collins English Dictionary), although “an historian” is retained in more dialects than “an hotel”.

Before abbreviations, the choice of “a” / “an” depends on how the abbreviation is pronounced:

“a NATO spokesman” (because “NATO” is pronounced /'neItoU/ or “nay-toh”) “an NBC spokesman” (because “NBC” is pronounced /Enbi:'si:/ or “en-bee-see”) “a NY spokesman” (because “NY” is read as “New York”).

Is it a FAQ or an FAQ? If you say “fack,” use “a”. If you say “eff-ay-cue,” use “an”. Such recent terms do not have a single, standard pronunciation. For a report on how people say FAQ, URL, and so on, see


If it begins with a vowel sound (not letter), you use “an”. Like “a uniform”, “an hour”
“el see dee” begins with a vowel sound, there for “an”. GPS (“gee pee es”) begins with a consonant sound, therefore “a GPS device”

PS. They’re not acronyms because they are not pronouced as a word, but initializations. :grandpa:

Rule: Use “an” before words that start with a vowel sound; otherwise use “a”. It doesn’t matter if the letter itself is a vowel or consonant; what counts is the initial sound.


an MBA degree
an hour
a university
a historic occasion

a FAQ (if you pronounce it “fak”)
an FAQ (if you pronounce it “ef ay cue”)

a herb (if you’re from the UK)
an herb (if you’re from the US)

Perfect. Thanks for the links too.

Dear Skullboy,

I hope you have learned something from all of this. Actually, Madame Blavatsky wrote a quite extensive passage in her works on automatic writings about the proper use of articles preceding a noun.

So, you see that the article should proceed the sound and not the letter.

That is why so many Taiwanese–what the hell, foreigners–speak such lousy English and are always ready to correct ours. They just ain’t figgerd out them damned acronyms. Yet.