'a' and 'an' undefined article usage


This is a simple question concerning undefined articles usage. I have a doubt if the an should be used when the next word to it starts with vowel, or it is related to the noun.

I though it was related the the following word, if I used an adjective as the sentence:

undefined article old man

would be:

an old man


a old man

But I saw in this site that the author writes: An RE (which means Regular Expression) what made question it.

How the an and a usage works?


Posted 2013-08-21T17:23:28.450

Reputation: 221

Question was closed 2013-08-21T17:51:34.787

2(in a nutshell, "RE" is an initialism that is pronounced "Are ee", which starts with a vowel sound, which therefore calls for "an" as the article.) – Hellion – 2013-08-21T17:42:09.230


I think you will find the answer to your question here. The question is not identical but the answer should solve your problem.

– WendiKidd – 2013-08-21T17:51:30.020

@Hellion Ah ok… this would be applied for words with y and w with vowel sounds also? As an yellow car? – Werner – 2013-08-21T18:14:07.640

2"y" and "w" at the start of a word are not vowel sounds. the "already-has-an-answer-at" link that Wendikidd provided has full details. – Hellion – 2013-08-21T19:07:49.043

2@Werner Forget the idea that some letters are vowels and some letters are consonants. That's only useful if you're playing Wheel of Fortune. In linguistics, some sounds are vowels and some sounds are consonants. – snailplane – 2013-08-22T03:39:42.767

@snailboat Yeah, I think I understood it better now. The issue is that 'y' and 'w' have sounds of vowels for me as in 'yell' or 'world', which would be 'i' and 'u' at my language (don't know the correspondent phonetic symbol), but anyway people even downvoted my question haah. I dont want to be bothering other people. – Werner – 2013-08-22T12:45:58.290

@Werner Please don't worry about that. I think your question was fine, so I decided to upvote it back to 0 :-) Occasionally people downvote questions because they're duplicates (on the theory that you wouldn't ask a duplicate if you've shown research effort), but generally this is a bad idea; we like duplicates here on Stack Exchange because they usually ask the question in a different way, so they help people find the answer in the future. (Now that it's been closed as a duplicate, users who aren't logged in will get redirected to the other question when they load this page.) – snailplane – 2013-08-22T15:53:23.933


In English, the 'y' and 'w' sounds (written /j/ and /w/ in the International Phonetic Alphabet) are classified as semivowels. I've linked to Wikipedia so you can read more about them, but in short: even though they're "vowel-like" sounds, they're treated as consonants in English. Here's another page about semivowels that explains it in another way.

– snailplane – 2013-08-22T16:20:00.137

@snailboat: Thank you very much. I would happily give you 15 reputation for your answer, this was not explained there. Even if my answer could be found there, I think my question differs a bit from it, and your answer is much better than the ones provided there. To close the issue, a rule like if the following word starts with vowel sound but it is not started with 'y' and 'w', then I use 'an', otherwise 'a'? Sorry about my computer programing if then else addiction… – Werner – 2013-08-22T17:28:34.353


The other linked question is indeed not identical to this one, but the core issue is the same. Use "an" when the next word (or abbreviation, or acronym, or symbol) is pronounced with a vowel sound; use "a" when the next part of the sentence is pronounced with a leading consonent sound. Thus: an FBI agent, an hour from now, a uniform distribution, a UN meeting. More here.

– J.R. – 2013-08-22T18:04:48.463

@J.R. I see, great example for 'a uniform' and a 'UN', so when the words sounds like 'y' it will not be an then. Thanks, now I completely understood. – Werner – 2013-08-22T18:22:33.937

No answers