Do you use “a” or “an” before acronyms?

Question

99% of the time, I'm clear on when I should use "a" versus "an." There's one case, though, where people & references I respect disagree.

Which of the following would you precede with "a" or "an," and why?

• FAQ
• FUBAR
• SCUBA

[Note: I've read the questions "A historic..." or "An historic…"? and Use of "a" versus "an", but the rules given there don't necessarily apply here.]

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[Edited to add]

Here's a shorter (and hopefully clearer) version of the question… In written English, which is correct (and why): "a FAQ" or "an FAQ"?

Some references with differing opinions:

• an: the UC San Diego Editorial Style Guide and Apple Publications Style Guide (page 69)
• a: the Microsoft Manual of Style for Tech Publications, 3e
• either: the alt.usage.english FAQ and Yahoo! Style Guide

Answer 1

It depends on whether the abbreviation is an acronym or an initialism. As "fubar" and "scuba" are usually pronounced as a word (making them acronyms), it would make sense to say "a fubar" and "a scuba diver". "FAQ" is a bit harder, because I have heard people say it like an initialism: "‹f›‹a›‹q›", while others pronounce it as an acronym /fæk/. Therefore, one should write either "a FAQ" or "an FAQ" depending on how that person pronounces it, ie, whether it is an acronym or an initialism.

Answer 2

Note: Some of this information may be extraneous, but take it for what you will!

In general, some acronyms represent nouns, others verbs or adjectives. If it represents the former, I see no problem with prefixing with an (in)definite article (a/an).

scuba is listed as a noun (lower-case) rather than an acronym in most dictionaries these days. It is of course derived from an acronym, but has evolved into a word in its own right (laser would be another example).

FAQ is an acronym, but is very commonly used as a noun - "a list of frequently-asked questions".

FUBAR has various definitions, but it's normally interpreted as an adjective (at least by the original military one).

Hence, I would happily prefix scuba/SCUBA with a/an, but definitely not FUBAR.

All these words begin with hard consonants, and thus should always be prefixed with a. Saying that, some people pronounce FAQ by spelling out its letters, in which case an is appropriate. I've never heard this done with the other two.

Answer 3

The important point to remember is the following:

Written language is a representation of the spoken word.

Thus, the answer is "If the word following the indefinite article begins with a vowel sound, use an; if it begins with a consonant sound, use a."

In the case of initialisms and acronymns, use the exact rule above. For initialisms (e.g. "US"), the individual letters are pronounced. With what sound does the first pronounced letter begin? In the example "US", the first sound is /j/ (or "y"). This is a consonant sound, despite the letter "U" being a vowel; thus, you use a, as in a US dollar.

Contrast this with the initialism "RPM", which begins with the consonant "R" but is pronounced starting with /a/; thus, you use an, as in an RPM counter.

Answer 4

The rule about the usage of a and an as indefinite articles is that an is used before a vocal sound.

• a warranty
• a user (because the u is pronounced like a y)
• a man
• an angel
• an information

When used before an acronym, the rule is still valid, but which article to use depends from how the acronym is pronounced (letter by letter, or like if it would be a word).

• an MP3
• an RPG
• an FBI agent
• a GPS device

As example of acronyms that are pronounced as if they would be a word, I can think only to laser and radar, but those words (which are reported to be acronyms from my dictionary) are probably perceived as words; therefore, they are not good examples.

Answer 5

Like @Vincent McNabb said, it is a question of whether the word is used as an initialism (like HTML) or a acronym. When in doubt, as with FAQ, I would defer to the initialism form ("a FAQ") as it suggests in Wikipedia:

There is also some disagreement as to what to call abbreviations that some speakers pronounce as letters and others pronounce as a word. For example, the terms URL and IRA can be pronounced as individual letters: /ˌjuːˌɑrˈɛl/ and /ˌaɪˌɑrˈeɪ/, respectively; or as a single word: /ˈɜrl/ and /ˈaɪərə/, respectively. Such constructions, however—regardless of how they are pronounced—if formed from initials, may be identified as initialisms without controversy.

Answer 6

It doesn't make any difference at all whether the article is modifying an acronym, an initialism, a proper noun, a French borrowing, or anything else. English article form is determined solely and entirely by pronunciation. And not at all by spelling.

The rule for the pronunciation of articles in English -- definite and indefinite -- is that they have one form before consonants (note, real consonants -- sounds -- not "letters" in a writing system), and a different form before vowels (ditto).

Hence, how you say it is what counts. Nothing else does.

• Before vowels -- Indefinite an /ən/ and Definite the /ði/:
  an hour, an SOS, an A-to-Z selection, an EE degree, an idiot
  the hour, the SOS, the A-to-Z selection, the EE degree, the idiot (all pronounced /ði/)

• Before consonants -- Indefinite a /ə/ and Definite the /ðə/:
  a URL, a snafu, a Charlie Foxtrot, a moron
  the URL, the snafu, the Charlie Foxtrot, the moron (all pronounced /ðə/)

Most native English speakers never notice that there are two different pronunciations for the, but non-native English speakers need to know this immediately.