Grammar Tips & Articles »

"A" vs. "An" - When to Use

This article is about "A" vs. "An" - When to Use — enjoy your reading!

2:18 min read
  Ed Good  —  Grammar Tips
Font size:

A Historic Topic - A vs. An

Writers sometimes confuse the use of the articles a and an. We were all taught that a precedes a word starting with a consonant and that an precedes a word starting with a vowel (a, e, i, o, u, and sometimes y).

Here’s the secret to making the rule work: The rule applies to the sound of the letter beginning the word, not just the letter itself. The way we say the word will determine whether or not we use a or an. If the word begins with a vowel sound, you must use an. If it begins with a consonant sound, you must use a.

For example, the word hour begins with the consonant h. But the h is silent, so the word has a vowel sound. Hence:

an hour

The rule works the other way as well. Take the word university. It begins with the vowel u. But the u is pronounced as if it begins with the consonant y. Hence:

a university

But consider the word umbrella, also starting with u. It starts with the vowel sound uh. Hence:

an umbrella

Another vowel with a consonant sound is o. When spoken, the letter can sound as if it begins with the consonant w. Thus, we use the a:

a one-room apartment a once-famous actor

Articles with Words Beginning with ‘h,’ a or an

The consonant giving us the most trouble is probably h. When the h begins a word and the first syllable is strongly pronounced, you should use a.

a history of Europe (accent falls on his) a hero (accent falls on he)

But when the beginning h is weakly pronounced (historic, habitual), you may use an, especially in British English.

an historic occasion (hisTORic) an habitual offender (haBITual)

But these usages are becoming increasingly old-fashioned, so you may also use a.

a historic occasion a habitual offender

Articles with Acronyms, a or an

Finally, the rule applies to acronyms as well. If you pronounce a letter as a letter and it begins with a vowel sound, you should precede it with an. The consonants with vowel sounds include f, h, l, m, n, r, s, and x.

He flew in an SST. He fired an M‑1. He attended an FDA hearing.

By the same token, if a vowel letter, with a consonant sound, is pronounced as a letter, you should use a.

He made a U‑turn.

Got it? So what is your grade?

An A? A B? Surely not an F.

Hard Copy

You may download our entire discussion of the Parts of Speech. Simply download the Grammar eBook Understanding the Parts of Speech.


Previous: A, An, The - The Articles

Next: Other One-Word Adjectives

Rate this article:

Have a discussion about this article with the community:

  • kevinw.66518
    Totally lost now :(
    LikeReply 21 year ago
  • muhammady.49266
    While using the term NCS (Networked Control System), should we use the term as 'a NCS' or 'an NCS'
    LikeReply2 years ago
    • bradleyw.21835
      If you say in your mind when you read the letters NCS ("en see es:"), then the letter N is pronounced beginning with a short "e" sound. So you would use "an NCS". If you say in your mind, Network Control System when you see the acronym, then you would use "a NCS" as YOU read this as "a Network Control System" even though there are only 3 letters written in the document. 
      LikeReply 12 years ago
    • thel36acyheres
      I thought U referred to the record label NCS (NoCopyrightSounds)
      LikeReply5 months ago
  • Trolley2991001
    990 stars
    LikeReply 12 years ago
  • goode33
    what about symbols like ~ for approximately before a word or number. Do you use the sound of the symbol or the word after ( an ~3 acre area or a ~3 acre area)
    LikeReply 13 years ago
    • bradleyw.21835
      If you say "approximately" when you read it (or say it in your mind), then you use "an". If you skip over the "~" when you read it, then you use "a".
      LikeReply2 years ago
  • Paul
    What about the following?
    An Historic Neighborhood Community
    A or An
    LikeReply3 years ago
    • bradleyw.21835
      The author talks about this. Look in the article for "historic".
      LikeReply 12 years ago
  • Noisha Studieren
    Noisha Studieren
    I am still thinking what are we supposed to look for then? Are we only supposed to look for ah and uh vowel sound?
    Like h silent, ah=an for hour and uh/uhm= an for umbrella?
    If a vowel or word gets yu vowel sound then that becomes a ?
    Trying to understand this interesting concept :) 
    LikeReply3 years ago
    • Gina N
      Gina N
      it is very simple...if a word begins with the sound of a vowel then you use "an" before it. If a word begins with the sound of a consonant then you use "a" before it
      LikeReply 53 years ago
  • Sathira Kumarasinghe
    Sathira Kumarasinghe
    LikeReply 13 years ago
  • Jose Alberto Justiniani
    Jose Alberto Justiniani
    This is gold, Jerry. Gold!
    LikeReply 44 years ago
    • Michael Morales
      Michael Morales
      these pretzels are making me thirsty
      LikeReply 23 years ago
  • Noisha Studieren
    Noisha Studieren
    Most of the parts were quite helpful. Thank you.
    I am not sure about U-turn though.
    LikeReply 24 years ago
    • Claudia Carlsen
      Claudia Carlsen
      It's definitely a U-Turn. Saying "an U-Turn" makes no sense.
      LikeReply 34 years ago
    • Bob Hanson
      Bob Hanson
      A is used with a U-turn because the hard U has a Y sound.
      LikeReply 34 years ago
    • Noisha Studieren
      Noisha Studieren
      Thank you guys
      LikeReply 14 years ago
    • Stefan Alexandru Kocsis
      Stefan Alexandru Kocsis
      Claudia Carlsen it'll sound like a new turn
      LikeReply3 years ago
    • STANDS4
      Claudia Carlsen Indeed...
      LikeReply3 years ago
  • Rehema Waithaka
    Rehema Waithaka
    I've been speaking english all my life and this info just never occured to me. I'm quite mind blown!
    LikeReply 24 years ago
  • Rick Papineau
    Rick Papineau
    SST is not an acronym. M-1 isn't, nor is FDA.

    Should we trust your opinion when your article includes such errors?
    LikeReply4 years ago
    • Claudia Carlsen
      Claudia Carlsen
      SST stands for supersonic transport. I would call that an acronym. The Free Dictionary places M-1 under an acronym listing. FDA is an anacronym that stands for Food and Drug Administration. What is your definition of an anacronym? 
      LikeReply 44 years ago
    • Tams Fletcher
      Tams Fletcher
      Claudia Carlsen An acronym is a type of abbreviation in which the first letters of the words being abbreviated form a pronouncable word such as NASA, LASER, and RAM. In contrast, an initialism is not pronounced as a word, for example, FDA, M-1, SST.
      Dictionaries are starting to define acronym to include initialisms because they are so commonly confused. 
      LikeReply 44 years ago
    • Talita Brits
      Talita Brits
      Tams Fletcher Thank you Tams, I learned something new today. Both from you and the article. However splitting hairs apart, this article was already a lot for me, someone who speaks very good english. I can imagine they wanted to keep it a bit simpler because otherwise people who really want this information (English language students) would not be able to find this article useful, but just too overwhelming. 
      LikeReply 23 years ago
  • Elvie Pacturan
    Elvie Pacturan
    thanks for the useful info
    LikeReply 24 years ago
  • Aman Sandhu
    Aman Sandhu
    Thanks for these tips! I just read a publicly posted US government document where they used "a" before the abbreviation "FFS" and it seemed wrong to me. Your article confirmed that my teachers in India taught me correctly. 
    LikeReply 14 years ago
  • Levi Hawj
    Levi Hawj
    Why teachers! WHY! (to my HS teachers)
    LikeReply 14 years ago
  • Marcangy Cange
    Marcangy Cange
    thank you
    LikeReply 14 years ago
  • Thomas Snyder
    Thomas Snyder
    Cleared up a debate at work...I was wrong.
    LikeReply 25 years ago
  • Terrie Thorn Bruner
    Terrie Thorn Bruner
    Great information. Very easy to understand and use. You know more than all the experts!
    LikeReply 45 years ago
    • STANDS4
      Thanks Terrie, appreciated!
      LikeReply5 years ago
  • David Parker
    David Parker
    Well done.
    LikeReply 16 years ago
    • STANDS4
      Thank you, David!
      LikeReply6 years ago
  • Claudia Niño
    Claudia Niño
    Very usefull post. Thanks to Kathleen for the addition.
    LikeReply 26 years ago
  • Bob Harris
    Bob Harris
    Recently in th newspaper there was reference to "an New Jersey...: I have seen this before elsewhere-Why?
    LikeReply 17 years ago
  • Kathleen Leger
    Kathleen Leger
    Ahead of the letter R when it's the first letter in an abbreviation. As in "An R.O.E." or "A ROE"
    LikeReply 17 years ago
  • Murray Callahan
    Murray Callahan
    Great post but not awsome, things like the Aurora Borealis are awsome!
    LikeReply 37 years ago
  • Gage Preston
    Gage Preston
    Awesome post!
    LikeReply 27 years ago
    • STANDS4
      Thanks Gage!
      LikeReply7 years ago
  • Chip Jones
    Chip Jones
    an independant organization-OR-a independent organization?
    LikeReply 17 years ago
    • Karen Everett Lewis
      Karen Everett Lewis
      An. The 'n' makes the pronunciation easier, which is the origin of "an" vs. "a".
      LikeReply 27 years ago
    • Chip Jones
      Chip Jones
      Karen Everett Lewis There is a vitamin advertisement on TV and the girl says "the vitamins are approved by a independent organization". It sounds wrong!
      LikeReply 27 years ago
    • Claudia Carlsen
      Claudia Carlsen
      Chip Jones That's definitely wrong. I am finding several wrong usages online these days. There are people who are using "a" incorrectly. It's becoming the norm and it's annoying.
      LikeReply4 years ago
  • Piku Samanta
    Piku Samanta
    o ho god why are you create the english language.?
    LikeReply 38 years ago
  • Stanley Clarke
    Stanley Clarke
    Find it a little confusing ,with the "an" rule must follow consonants is not consistent .Surely there must be an easier explanation!!!
    LikeReply 68 years ago
    • Teressa Allen
      Teressa Allen
      There is Stanley. If you are talking about AN ITEM then use AN. If you are talking about two or more things, then use AND. (She and I) (An apple)
      LikeReply 17 years ago
    • Kanocia Gayden
      Kanocia Gayden
      Teressa Allen what about for a & an (an elephant) OR (an hour) or (a hour)
      LikeReply 17 years ago
    • Jin KLo
      Jin KLo
      Kanocia Gayden i'ts all about the sound.,, :D
      LikeReply 27 years ago


Use the citation below to add this article to your bibliography:


""A" vs. "An" - When to Use." STANDS4 LLC, 2024. Web. 13 Jun 2024. <>.

Free, no signup required:

Add to Chrome

Check your text and writing for style, spelling and grammar problems everywhere on the web!

Free, no signup required:

Add to Firefox

Check your text and writing for style, spelling and grammar problems everywhere on the web!


Free Writing Tool:

Grammar Checker

Improve your grammar, vocabulary, and writing -- and it's FREE!


Are you a grammar master?

Identify the sentence with correct use of the past perfect tense:
A We will have completed the project by Monday.
B They are going to the concert tonight.
C She finished her homework before dinner.
D She had already eaten when he arrived.

Improve your writing now:

Download Grammar eBooks

It’s now more important than ever to develop a powerful writing style. After all, most communication takes place in reports, emails, and instant messages.