Trying to figure out whether to use the indefinite article a or an before a noun can be tricky for inexperienced English users. Many people seem to think that you should use a before a consonant and an before a vowel, but it is not quite that simple. The actual rule is that a is used before a consonant sound and an before a vowel sound — these do not always match up with the letter itself! For example, one of the most common mistakes I have been seeing recently is the use of “a hour” instead of “an hour”. The latter is correct because the word hour actually begins with an o (vowel) sound; the h is silent. Conversely, we would say “a Ouija board” instead of “an Ouija board” because Ouija is pronounced with a w (consonant) sound. This rule also extends to acronyms. For example, I have lost count of the number of times that I have cringed whenever I see someone write “a HYIP” on a forum or blog. This should be written “an HYIP” because the letter H is pronounced with an a (vowel) sound. However, if we were to write the acronym out we would write “a High Yield Investment Program” because the consonant h sound is now being pronounced as part of the word high.
Acronyms: A vs. An Usage Before A Given Letter
Because this rule can be tricky, especially for people who are hearing impaired and therefore may be unaccustomed to hearing what the letters sound like, I have attempted to clarify things below by first listing all of the letters that are initially spoken with a vowel sound and therefore require an before them if the letter is used in an acronym. All other letters are initially spoken with a consonant sound and will require a; these are listed in the second line below:
If the acronym begins with these letters, use an: A, E, F, H, I, L, M, N, O, R, S, X
If the acronym begins with these letters, use a: B, C, D, G, J, K, P, Q, T, U, V, W, Y, Z
For example, we would write an FBI agent, an SEO, and an LP member, but we would write a YMCA member, a QC inspector, and a USB port. Now we can look at some examples from the Internet where a and an have been used incorrectly:
Incorrect: New teeth in a hour is worth smiling about — headline of an online newspaper article at living.scotsman.com
Correct: New teeth in an hour is worth smiling about
Incorrect: I’m a idiot for buying this book! — reviewer “Kimberly” at search.barnesandnoble.com
Correct: I’m an idiot for buying this book!
Incorrect: Our Engineering and Technical division is currently working with a leading producer of steel related products in Plymouth, MN which has an immediate need for an Quality Technician. — job posting at aol.careerbuilder.com
Correct: Our Engineering and Technical division is currently working with a leading producer of steel related products in Plymouth, MN which has an immediate need for a Quality Technician.
Incorrect: I certify that I am an United States resident licensed to practice law in Wisconsin, and that all of the information I have provided is true. — Notary Public application for Wisconsin attorneys
Correct: I certify that I am a United States resident licensed to practice law in Wisconsin, and that all of the information I have provided is true.
Quick Summary: If in doubt about whether to use a or an, simply pronounce the word that is to appear after the article. If the first sound pronounced is a vowel, use an; otherwise, use a.
Poster Comment:
This is something I have been noticing for some time. Many otherwise intelligent--some of them probably genius level intelligent--continually get this wrong and it is not complicated. At least I don't think it is. Anyway, just posting it as a "public service." >(;^{]