When to use “an”

By Maeve Maddox

David asks

When to use a or an? a horse, an apple. A SUV or an SUV?

The rule is to use the article a before words beginning with a consonant sound and an before one beginning with a vowel sound:
a dog
an eel
an hour

Disagreement exists with certain “h” words. For example, not everyone pronounces the h in herb, homage, and humble, but more and more native speakers do.

Depending upon vocal stress, one might hear either “a historic occasion” or “an historic occasion.” Most American speakers would probably say “a historic.” Either is correct in writing.

About the only common English “h words” that definitely require an are heir/heiress/heirloom, honest, honor/honorable, and hour:
an heir to the throne
an honest man
an honorable woman
an hour before

Which indefinite article to use before an abbreviation, a numeral, or a symbol, depends upon pronunciation.

Some examples from the Chicago Manual of Stylee:

an NBC anchor
a CBS anchor
an @ sign

CMOS also points out two possible readings of MS:

an MS treatment

Here the letters stand for “multiple sclerosis” and are read as “Em S.”

a MS in the National library

Here the letters stand for “manuscript” and are customarily read as “manuscript.”

You’d write “an SUV” because SUV is pronounced one letter at a time and the sound of S is “ess.”

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13 Responses to “When to use “an””

  • adrienne

    I thought it was automatic to use an in front of a vowel. I never gave much thought to an hour. I always wrote it like that because that’s how I say it.

    Thanks for the tips.

  • Anne Wayman – About Freelance Writing

    I’m so grateful I’ve got a decent ear for these things… thank my parents often for growing up hearing English used well.

  • victoria

    hi…thank you for grammaring to this website so i will always go to this website so im very thankful to this website because im veryu thankful to this website….hehehe

  • Zaaa

    what about the word unified ?

    if i wana say : in his search for (a/an) unified answer to these problems . which should i use ?

  • brayden

    use a, an sounds terrible .. 😛

  • Neil

    It would definately be ‘a’ for unified. if you think how a child would say ‘U’ when first learning phonetically it would be pronounced ‘uhh’ as in up. Unified starts with U’s ‘name’ which is pronounced ‘yew’. Yew = a and uhh= an. As in ‘an umbrella’ or an ‘utter nonsense’ as opposed to ‘a university’ or ‘a useful piece of information’ which I hope I just provided! 🙂

  • anup

    for e.g. an MBA
    it is because if we pronounce the letter “M”, we speak ’em or am’. Both starts with vowel. So “an” is used used here same in the case with the word hour and other

  • anonymous

    Here’s an article usage with acronyms that can screw with your noodle.
    “Yesterday, a/an NATO official reported that no news is good news.”
    The question is which to use? NATO itself is an acronym but is commonly pronounced as a word. Now I am not a literary scholar but have always felt that the article usage should be used in the manner of what the acronym actually means.
    My point being is that if you write the article (a/an) to match what the word is for the first letter of the acronym, then you can really never be wrong. Thats just my opinion however. 🙂

  • qazi

    should i use ‘a’ with NGO or ‘an’ ?

  • Oscar Torres

    Thanks for a supporting reference on english grammar.
    As a foreigner in the US, and being english my second language I learned grammar rules and try to stick to them always.
    Often, I am seen either as a foreigner trying to speak english or as a petulant trying to teach americans how to speak well.

  • Valchemishnu

    Thank you very much. I saw the use of both an and a before herbal plant. I wondered why and checked this site and is very satisfied.

    “Always use an heir”- I didn’t know that. This is a great site. Hope you will add more.

  • Eric

    Just saw a local billboard advertising, “This is a good place to buy a “RV”. This one just about unhinged me!

  • Mark M

    It isn’t absolutely to do with “pronunciation”, people!
    The use of article “a”/ “an” is about determining the vowel/ first syllable of a noun (i.e. a/e/i/o/u/ some h).
    i.e. a United States citizen / an E.M.S. (Emergency Medical Services)
    an ozone layer/ an umbrella/ an umpire/ an ounce

    So, using “an SUV” is controversial. It isn’t even pronounced as a vowel sound; not sure how some would think “an SUV”?

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