261

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.]

[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:

Laurel
  • 66,382
Dori
  • 3,946
  • 28
    This does raise questions about when there are multiple common pronunciations of the acronym. Like "SQL" is sometimes pronounced "es-kew-el", and sometimes "sequel". The former would call for "an" and the latter for "a". I think, though, that we always choose "a" or "an" based on pronunciation of the acronym and not the spelled-out words, e.g. "an SST", as in "an ess-ess-tee", not "a supersonic transport". – Jay Sep 30 '11 at 14:32
  • 8
    @Jay SQL: In which case the writer picks their own style (or follows the in-house style) and uses it consistently. – Hugo Sep 30 '11 at 15:10
  • 8
    Or rephrases all sentences with SQL to avoid putting either "a" or "an" in front of it. – yoozer8 Sep 30 '11 at 17:25
  • 6
    @Jim: While I admit to sometimes rephrasing a sentence to avoid a spelling or grammar problem, that is the coward's way out! – Jay Oct 04 '11 at 15:09
  • RPG, when spoken, sounds like "are pee jee," thus it's prefixed with an "an." –  Feb 06 '11 at 04:48
  • 12
    "An RPG". The controlling factor is whether it's spoken with a vowel sound. (So "an hour", "a unicorn", etc.) – chaos Feb 06 '11 at 04:46
  • 1
    The last four links are obsolete (the importance of quoting relevant passages being the moral here, I think) – Mari-Lou A Apr 05 '14 at 05:54
  • 2
    @Village nearly all the answers agree on one thing, that the placement of a vs an depends on pronunciation, if you pronounce FAQ as fack it follows a; if you spell out each letter, ef ei kju: then an precedes it. But if you're adamant in receiving an answer with credible and/or official reference then it has been provided here http://english.stackexchange.com/a/47600/44619 – Mari-Lou A Apr 05 '14 at 06:06
  • in almost all cases of "a" vs. "an", you get the answer by just trying them both, and picking which one sounds more natural. This might be because I'm a native speaker though. I imagine it would be tougher when learning the langauge. – Cruncher Jul 14 '14 at 19:37
  • possible duplicate of When should I use "a" vs "an"? – FumbleFingers Nov 22 '14 at 12:51
  • This question addresses a special case of the general rule, which is only covered briefly in one relatively low-rated answer at the other question. I don't believe it should be considered a duplicate. – phenry Nov 24 '14 at 16:49
  • Nothing special about "F" -- it depends on whether the abbreviation is pronounced (read) as such or in an expanded form. HTH. – Kris Nov 12 '18 at 10:05
  • 2
    How do you pronounce the letter "f"? I pronounce it as *ef* – Mari-Lou A Nov 12 '18 at 10:16
  • @Mari-LouA yeap you are right haha it should be pronounced as “ef” but i think while i was reading the text, I unconsciously pronounced the abbreviations as not shortened forms – Nayeong Kim Nov 12 '18 at 10:21
  • @Jay this is an old question, but popped up as a duplicate of a recent question. From what I can remember, the only time "SQL" is pronounced as "sequel" is when it's the product name "Sql Server" (note the lack of capitalisation). "SQL" the acronym which stands for "structured query language" should be "ess que ell", also when it's part of the product MySQL, for example. – Aaron F Jun 02 '21 at 19:39
  • 1
    @AaronF Database people go back and forth on this. Search for "how pronounce SQL" and you get a slew of articles with various people's opinions. https://duckduckgo.com/?t=ffab&q=how+do+you+pronounce+sql&atb=v171-1&ia=web I think that most people I've worked with pronounce it "sequel". The MySQL folks same somewhere on their site that they pronounce their product "my es-que-ell" but they have no objection to "my sequel". I think we should have a fight to the death over this. – Jay Jun 03 '21 at 16:38
  • @Jay "I think we should have a fight to the death over this" +1 :-D – Aaron F Jun 03 '21 at 17:39
  • @AaronF: There are two camps. Oracle, MySQL, etc. say "sequel" (it's an acronym). Microsoft, IBM, etc. say "ess keq ell" (it's an initialism). I think most people say "sequel" in NoSQL, but I could be wrong. – Drew May 31 '23 at 21:02

10 Answers10

228

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" (/fæk/) or "an FAQ" (‹f›‹a›‹q›) depending on how that person pronounces it, ie, whether it is an acronym or an initialism.
Snostorp
  • 163
  • 2
  • 11
Vincent McNabb
  • 9,176
  • 22
    Thanks for the teaching :-) Indeed there is a difference in the strict sense :-) So is CD-ROM an acronym or an initialism? – Vincent McNabb Aug 16 '10 at 09:08
  • 1
    +1 (more if I could) for expaining that acronyms are pronounced as words. You'd be surprised how many people don't know that (and actually argue that it's not true). – Matt Hamilton Aug 16 '10 at 09:24
  • @Vincent: what about in written English? Let's say I'm writing something where—while I know which I use—I don't know if the reader says "fack" or "eff-ay-que." Will there always be readers who think I was wrong? – Dori Aug 16 '10 at 21:15
  • 4
    @Dori - yes. Whichever way you write it, it will trip up some readers. The Corpus of Contemporary American English (COCA) lists two results for "a FAQ", and one result for "an FAQ", so "a FAQ" is probably more common. Google also shows a preference for "a FAQ". – Vincent McNabb Aug 17 '10 at 00:12
  • 5
    The whole “ acronyms must be pronounced as words” distinction appears to be one that is only made by dictionaries. From what I can tell, any abbreviation that is made from initials is called an acronym if it is pronounced differently from what the initials stand for. – nohat Aug 18 '10 at 14:56
  • 4
    It appears that the answer is: "there is no definitive answer to this question." Not exactly what I'd hoped, but as this was the only answer that responded to the question I asked, I guess that makes it the best. – Dori Aug 20 '10 at 04:04
  • 2
    Similar problem with SQL. If you pronounce it es-queue-ell then it's "an SQL database", if you pronounce it sequel then it's a SQL database – mgb Apr 06 '11 at 04:23
  • 4
    @mgb Amazingly. If I just "a SQL database" I will automatically pronounce it sequel in my head without even thinking about it. Using "an" I will automatically spell it out in my head. – Cruncher Jul 14 '14 at 19:36
  • (Not sure if this warrants a separate question.) In scientific papers, it is common to define abbreviations just to save space. For example, "semimetal" would be abbreviated by SM in a given paper, but is not a universal abbreviation comparable to CD-ROM. After being corrected by proof-readers regarding the use of a/an many times, I have come to accept that it should be "an SM" even though in my head I replace SM by semimetal while reading. Would you say that the above rules apply in the same way to such abbreviations? (To my confusion, in my last paper, the editor insisted on "a SM"). – painfulenglish Aug 20 '14 at 10:17
  • 1
    @Jay I found this thread because of a code review I'm working through (I work as a software engineer) and acronyms are just part of life in this business. It's interesting to learn the distinction between acronym and initialism. However, I thought I'd toss out that I've heard SQL pronounced squeal as well. :-) – Andrew Falanga May 27 '15 at 18:53
  • This could be a great answer; admittedly, one that I agree with. However from my POV it seems like mere opinion. Some citations to hard references would make it even better (and would earn it an upvote). – chharvey Jun 19 '15 at 02:37
  • 1
    CD is clearly an initialism; if it were a word, it would be pronounced something like "could" or "cud" or "kid". But we say "see-dee". That has no effect on the article to use, however, because both "see" and "c*d" start with a consonant sound rather than a vowel sound.

    "ROM" by itself is more interesting. In my experience it is usually pronounced like a word, "rom" /rɔm/ (phonetic vowel value depending on dialect), so you would say "a ROM". But if you pronounce it as the individual letters "ar-oh-em", it' would be "an ROM".

     – Mark Reed Dec 18 '16 at 16:34
  • Who on Earth pronounces FAQ as "fake"? Never heard that in my life. – BadHorsie Sep 05 '17 at 10:09
  • 1
    @BadHorsie Nobody as far as I know. I've head it pronounced /fæk/ which rhymes with "back" – Vincent McNabb Sep 06 '17 at 01:04
  • Perhaps you could add supporting evidence. That's a lot of credit for what would now be seen as an unsatisfactory answer (though almost certainly correct). – Edwin Ashworth Oct 29 '19 at 11:24
  • I think your first sentence is a perfect basis of what to use. Perhaps adding the word "official" in the sentence would resolve the difficulties from people using acronym vs initialism. "It depends on whether the abbreviation is officially an acronym or an initialism" - i.e. if "FAQ" is officially an initialism then "an" is simply the correct thing to use. – James Apr 28 '21 at 12:45
  • Interesting scenario I thought of today is that for certain letters the pronunciation itself would be different even if it's only an initialism and never an acronym. Something like HTTP as an initialism for american english would be 'aitch' ttp and thus an HTTP request, but for some accents of British english it could be pronounced 'haitch' ttp and thus a HTTP request. I think the former would the more common pronunciation but I'm american so what do I know. – DLeh Aug 11 '21 at 16:39
136

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.

Spoxjox
  • 1,946
  • 1
    'Written language is a representation of the spoken word.' Yes, but certain conventions are used that are not etically transparent. Does one read out the period's in U.S. (probably still more commonly encountered than US)? How would an expert in spoken English who has never seen written English know not to read them out? The rule Use 'an' if and only if the following sound is ... is certainly almost universal (there remains at least one grey area), but you really need to add supporting evidence. Some arrogater (String & Write, say) may have forced a less sensible 'rule' on us in the past. – Edwin Ashworth Oct 29 '19 at 11:34
  • @EdwinAshworth I doubt one can be an expert in spoken English without having seen written English. – Lambie Dec 12 '22 at 16:42
34

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

  • A warranty (/ˈwɑːrənti/)
  • A user (/ˈjuːzər/)
  • A one-way (/ˈwən ˌweɪ/)
  • A man (/mæn/)
  • An angel (/ˈeɪnʤəl/)
  • An information (/ˌɪnfərˈmeɪʃən/)

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 as a word).

  • An MP3 (/ɛm pi θri/)
  • An RPG (/ɑːr pi ʤi/)
  • An FBI agent (/ɛf biː aɪ/)
  • A GPS device (/ʤi pi ɛs/)
  • A NASA employee (/ˈnæsə/)
apaderno
  • 59,185
  • @chaos: It doesn't seem that I am the only one to refer to the NOAD; your comments about me (and not to my question) make me think you are saying that I am the only one reporting what the NOAD says, which is not true at all. It also seems that your comments are against me, not against using the NOAD as a reference. I don't think the NOAD is a substandard English guide, and there are many people who would not say the NOAD is a substandard English guide. – apaderno Feb 06 '11 at 08:57
  • 3
    @chaos: The distinction between acronym and initialism is a neologism that is not maintained by all writers or dictionaries. In fact, the Wikipedia page you linked cites The Cambridge Encyclopedia of the English Language: "However, some linguists do not recognize a sharp distinction between acronyms and initialisms, but use the former term for both" and Merriam-Webster's Dictionary of English Usage: "A number of commentators […] believe that acronyms […] pronounceable as words. Dictionaries, however, do not make this distinction because writers in general do not." Etc. – ShreevatsaR Feb 06 '11 at 11:53
  • 5
    @chaos: As a linguist, I don't consider people's actual usage to be the "lowest common denominator". Why should a self-declared grammar authority's arbitrary decision about the meaning of a word be inherently more "correct" than the way people actually understand the word? Language often isn't precise. There are those who construct artificially precise categories for English lexical items (that don't reflect usage) and then view those who don't conform to those distinctions as being sloppy or poor in their command of English. I see that as a waste of time — we don't learn anything that way. – Kosmonaut Feb 08 '11 at 14:33
  • 2
    The "acronym"/"initialism" distinction may not be universally accepted, but it's still probably worth mentioning in an answer that distinguishes between the two types of pronunciation of "acronyms". – Mark Reed Dec 18 '16 at 16:37
  • A united ......... – Zhang Apr 03 '19 at 07:39
  • @Zhang That is the same as a user. – apaderno Apr 03 '19 at 07:42
  • Just come back here. // 'The rule about the usage of a and an as indefinite articles is that an is used before a vocal sound.' is too simplistic; a second rule, and a third allied to traditionalism, must be seen with certain words beginning with h. This is discussed elsewhere. / Also, I think 'acronym' is now largely accepted as being confined to abbreviations pronounced as if they were words. – Edwin Ashworth Oct 09 '19 at 18:44
23

Vincent McNabb is correct. If you want evidence based on "credible and/or official sources" that this is the rule followed in formal English writing, here is my suggestion.

I ran Google searches on Google Books only, meaning the bulk of the search will be against professionally edited and published works, not random web sites. I searched only for phrases where the pronunciation of the acronym was relatively clear and consistent: for example, nobody pronounces "SCUBA" as "Ess Cee Yew Bee Ay" and nobody pronounces "FBI" as "Fibbi."

Here are the number of hits in the Google Books database for:

  • "A SCUBA": 49,800
  • "An SCUBA": 56
  • "A FBI": 16,000
  • "An FBI": 343,000
  • "A NASA": 264,000
  • "An NASA": 16,500
  • "A RGB": 7,130
  • "An RGB": 33,800
  • "A UPC": 11,800
  • "An UPC": 436

In each case, basing the article on the initial sound, rather than on the initial letter, is more common; in most cases substantially more common.

As a control, I also looked at two acronyms where both the initial sound and the initial letter are consonants.

  • "A VPN": 50,100
  • "An VPN": 960
  • "A OCR": 9,380
  • "An OCR": 1,870,000

Because "An VPN" and "A OCR" are incorrect based on any possible rule, we can conclude that the positive results are grammatical, OCR, or search engine errors. This suggests that the minority viewpoint on SCUBA, FBI, NASA, RGB and UPC are also smaller than they appear.

We can conclude that, based on evidence of usage among published documents digitized by Google Books, the preferred rule is to base the article on how the intended pronunciation of the acronym would be spelled phonetically.

chapka
  • 4,187
20

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.

Noldorin
  • 13,260
  • 2
    When used in the military sense, "fubar" would not have a(n) before it. However, when used in other senses where it is a noun, it would be perfectly fine. It would also be fine to say, "Man, this is a fubar situation". As the article refers to the noun, "situation", which is being modified by the adjective, "fubar". – Vincent McNabb Aug 16 '10 at 09:26
  • @Vincent: Yeah, but that's slightly beside the point. I mentioned that fubar is used as an adjective, this 'a' is just applying to the 'situation'. – Noldorin Aug 16 '10 at 10:13
  • @Noldorin I agreed with your point and added extra information. You are welcome to edit your post and clarify. – Vincent McNabb Aug 16 '10 at 10:45
  • 5
    The question is which to use between "a" and "an", not whether to use them. The part of speech has nothing whatever to do with this question: it's all on the pronunciation. – Colin Fine Aug 16 '10 at 13:20
  • @Colin: The question was not clear to me. It seemed to be asking too different things. Just because I provided more info that may have been necessary, think twice whether that really deserves a down-vote. – Noldorin Aug 16 '10 at 13:33
  • @Noldorin - yes, sorry: I downvoted and then thought better of it, but couldn't work out how to remove my downvote. It let me upvote to 1, but I couldn't see a way to set it back to 0. I still think that providing information extraneous to the question is unhelpful, but I would have removed the downvote if I could. – Colin Fine Aug 16 '10 at 17:05
  • @Colin, you can just click on the down arrow again and it will undo your vote, putting it back to 0. – kitukwfyer Aug 16 '10 at 19:47
  • @Colin: No worries. I fully admit that I may have provided some information that wasn't a response to the question; it happens when one reads the post too quickly. :) Also, you should be able to remove your down-vote as kitukwfyer said, or failing that, editing the post just before. – Noldorin Aug 16 '10 at 22:12
  • @Colin Fine: Try now? – Noldorin Aug 18 '10 at 08:31
16

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 (note, 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.

John Lawler
  • 107,887
4

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 ("an 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.

Lynn
  • 17,801
  • The initialism (non-acronym) is pronounced 'an FAQ'. – Edwin Ashworth Aug 17 '20 at 13:15
  • @EdwinAshworth FYI I interpreted Lynn's "a FAQ" as an acronym b/c it can be read as a single word (faq), which is how I normally hear it in videos but some people do read each letter separately. In any case, the answer provides a link and supporting evidence which is more than the majority of answers posted here. – Mari-Lou A Dec 12 '22 at 12:29
  • @Mari-Lou A I was addressing << I would defer to the initialism form ("a FAQ") >> – Edwin Ashworth Dec 12 '22 at 19:37
  • @EdwinAshworth Maybe Lynn will clarify one day Wikipedia: regardless of how they [initialisms] are pronounced, which, I think, means “a FAQ” is still acceptable. – Mari-Lou A Dec 12 '22 at 19:50
  • @Mari-Lou A << I would defer to the initialism form >> forces << ("an FAQ") >>. It is a restatement, not an identifier (restrictive) usage, which would be << I would defer to the initialism form "an FAQ" [as opposed to ...] >> – Edwin Ashworth Dec 12 '22 at 19:57
  • @Mari-LouA It was just a mistake. As Edwin points out, I recommended defaulting to the initialism, but then used the acronym version's article. I fixed it. I do think that either one is acceptable though. If I see "a FAQ" I would know that the writer intended the "fack" pronunciation. If I see "an FAQ", it would be the initialism "eff-ay-cue". – Lynn Dec 17 '22 at 16:33
3

Edit: I originally posted this answer to the question Is there an exceptional use of the article ‘a/an’? which has been merged with this one. The acronyms FTA and FC I refer to below are from that question.

Original answer: It is exactly as you said: an is used before words beginning with a vowel sound, not necessarily a vowel letter.

The acronyms you mentioned both begin with vowel sounds (/ɛf.tiˈeɪ̯/, /ɛfˈsiː/), so an is used before them. There are also words and acronyms that begin with a vowel letter, but not with a vowel sound: a UAV (/ju.eɪ̯ˈviː/), a union (/ˈjuːnjən/).

It depends on the pronunciation of the following word (not its spelling) whether you use a or an.

Lukas G
  • 205
1

Compare with an umbrella uttered as /əmˈbrelə/, versus a university uttered as /juːnɪˈvɜːsɪtɪ/. Though both begin with the same written vowel, they have a different sound at the beginning. Umbrella has a schwa, while university has a 'you'. It is the sounds rather that the written vowel that drive the choice of 'a' or 'an'.

It is similar with your question. "An Eff Tee Ay" or "an Eff See". It is the spoken'Eff', uttered with a vowel sound as /ef/, that drives the use of 'an' even though [f] is listed as a consonant.

Roaring Fish
  • 15,115
0

The problem with a vs an with acronyms and abbreviations is that you can't always be sure how the reader will read it. For example, some people might read SIN and say s-i-n while others might say sin, and yet others might say social insurance number. This means it's impossible to have a blanket rule, and therefore it only makes sense to do it however makes sense for yourself (and be consistent), or if possible, whatever makes sense for your audience.

Synetech
  • 2,333
  • (Surprisingly, nobody else mentioned that acronyms and abbreviations can be read with their constituent parts, nor suggested catering to the reader, so I figured I'd post a full answer instead of a comment. ) – Synetech Jun 08 '20 at 20:35
  • But the best answer is 'do what 95+% of proficient Anglophones do'. Pythons might pronounce SIN 'luxury yacht' say, but should not be accommodated. – Edwin Ashworth Aug 16 '20 at 16:23
  • What? Are you saying that you never say s-i-n? And where did you get your stats? How can you prove that 95% of people say sin? And even if that were the case, so what? Are you saying that 5% of people should just be ignored and go to hell? – Synetech Aug 16 '20 at 23:15
  • ELU looks at standard usage by proficient Anglophones. It is not targetted at catering for all possible misinterpretations / non-standard practices. Answers should reflect this view, found at the Help Center here. // If both acronym and initialism are commonly used and there remains a debate about which form of the indefinite article should (not might erroneously) be used, 'a', 'an' or 'a/an' are all available. I seem to remember one such example in another thread. – Edwin Ashworth Aug 17 '20 at 12:00
  • Your response is absurd. You still have not shown that 95%+ of Anglophones pronounce it in any specific way, but even if you somehow could show such statistics, that still wouldn't make it the "correct" way, and thus, your argument that any other way should be ignored and not mentioned is ridiculous. But then, I just noticed your other comments on this page, and it looks like you're a pedant who simply wants to argue with other to show how "smart" you are, so I won't be responding to any further replies from you since it would be pointless. – Synetech Aug 18 '20 at 13:21