A versus An: The Indefinite Article

A visitor wrote in to ask when to use “a” and when to use “an.” In particular, she wanted to know which of the following is correct:

  1. Citibank is a MNC Bank
  2. Citibank is an MNC Bank

The correct sentence is number 2.

The Rule

Use “a” when the following word begins with a consonant sound; use “an” when the following word begins with a vowel sound. What matters is how the following word is pronounced, not what it looks like. In the example sentence, “MNC” begins with a consonant, but it begins with the sound of the vowel “e,” since we would pronounce it as “em en see.”

Extra Credit

Some people, especially those who are trying extra hard to sound erudite, will use “an” before a word that begins with the letter “h,” such as “an historical artifact.” In the United States, this usage is incorrect. Instead, we write, “a historical artifact.” For a more detailed discussion of this issue, see “More on A vs. An” from Bill Walsh’s Sharp Points.

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14 Responses to A versus An: The Indefinite Article

  1. Michelle Harburg says:

    Would you say a universe or an universe? This seems to contradict the rule of using an before words that sound like a vowel. Please let me know! Thanks.

  2. Karl says:

    Hi Michelle, I would say “a universe.” The “u” in this case has an initial consonant “y” sound, so it doesn’t contradict the rule at all. Thanks for the question.

  3. Alex says:

    What about if used in front of numbers “a 3% discount” or “an 3% discount”??

  4. Karl says:

    Hi Alex. The same rule applies. Since “3%” begins with a consonant sound, you would use “a 3% discount.”

  5. kristi says:

    Would you use a RSS feed or an RSS feed?

  6. Karl says:

    Hi Kristi, I would use an RSS feed.

  7. adrian says:

    would you say “a html tag” or “an html tag” ? .. my guess is to use the second version

  8. Karl says:

    Yes, use the second one: “an HTML tag.”

  9. Niels Vagn Pedersen says:

    Just stumbled on this thread which made me aware of an apparent gap in my knowledge of the English language. My question relates to Karl’s answer # 2: So what you’re saying is that in English “y” is not a vowel? I’m asking because in Danish (which is where I’m from) and other Scandinavian countries “y” is definitely a vowel and it just didn’t occur to me that it would be any different in English. Interesting…so what are actually the vowels in English (I can figure out the consonants from there…:-) )?

  10. Karl says:

    Welcome, Niels!
    The letter “y” (and “w,” for that matter) is a tricky one in the English language. Sometimes it acts as a consonant, and sometimes it acts as a vowel. In the case of “yellow,” for example, the “y” is acting as a consonant, whereas in “snowy” it is acting as a vowel.
    In comment #2 above, I was referring specifically to the consonant “y” sound, because the sound is the determining factor for choosing the indefinite article to precede it (“a” or “an”).
    I hope that makes sense. Let me know if you would like me to clarify any further.

  11. Jennifer Stoepker says:

    Hi there,
    My coworker and I are trying to decipher the rules for “an” and “a”. Our question is in regards to the consonants F, M, N, R, S and X.
    Per your previous comments, it states: to apply the rule of the “sound” of the letter. So, are the above letters that we have listed ALL of the consonants in the alphabet that we would use “an” for? Specifically, we’re asking in regards to when you are actually saying the letter, not when the letter begins a word. And if so, is this because the sound of the letter actually being said starts w/ the “eh” sound like the vowel “e” or the “ah” sound like the vowel “a”?
    Please help us clarify…thanks – Agnes and Jennifer

  12. Karl says:

    Hi Jennifer,
    Yes, you would use “an” for the reason that you cited.

  13. Laura says:

    Would you use “a” or “an” in front of Eureka College?

  14. Karl says:

    Not sure why you would want to use either one in front of a singular proper noun, but if I were going to do it, I’d use “a.”