"A" Versus "An": An Article about Articles

10 December, 2021

Here’s a quick test on when to use a and an. Spot the errors:

I was at an historic occasion, a meeting at a hotel near an university to discuss an HUD directive, when my recorder ran out of power. For want of an AA battery, my records of the meeting were lost, and it was all consigned to no more than a * in an MS.

How many slip-ups do you count? There are actually six mistakes in there. Let’s see what they are—and why!

An Universal Rule

You probably learned in school that you use an before words that start with a vowel and a before words that start with a consonant. But that’s missing one useful detail: you use an before words that start with a vowel sound—including words like heir that are written with a consonant (h) that you don’t say—and you use a before words that start with a consonant sound, including the “w” sound in one and the “y” sound in useful. It’s one of the few truly consistent rules in English, but because our spelling isn’t always consistent with our pronunciation, people can get confused.

Back in the mists of distant history, the indefinite article was always an, which comes from the same root as one. But when people were speaking, if the next sound was a consonant, they got into the habit of dropping the n, and eventually it became the law in standard English: if the word after an starts with a consonant sound, an becomes a.

It’s true that there are varieties of English where, as Dickens’s Mr. Bumble said, “The law is a ass”—a is pronounced like A, as in “eh,” and used even before vowels. But in the kind of English you work on professionally, the law is so reliable you can use it to indicate, for instance, how a given speaker (or your house style guide) pronounces homage, whether certain acronyms are meant to be spelled out or pronounced as words (an HIV-positive person with a HER2-positive breast cancer), and whether you’re transcribing someone who speaks an “h-dropping” variety of English (an helicopter, also written an ’elicopter if you think the reader won’t get the idea).

Is a U a Euphonious Sound?

One point of historical—and international—contention is the sound at the beginning of words like euphonious. Some people have insisted that it is a vowel sound; they would say “an useful distinction.” But words such as you and youth start with exactly the same sound, and remember that it’s the sound, not the spelling, that governs the choice: we don’t say a heir or a MVP, for example. So unless you would say an youth—and you almost certainly would not—you have no reason to say an university or an UK government initiative.

Whose Department Is It Anyway?

Of course, if we pronounced UK as “uk” (rhymes with “luck”), then it would be an UK after all. And sometimes it’s not so obvious whether an acronym should be said as a word or as letters. One example that The Chicago Manual of Style gives is HUD. You may know it as the Department of Housing and Urban Development. But if you know it as “H-U-D,” then you are going against the current: the standard pronunciation is “hud,” rhyming with “thud,” and so it’s a HUD directive. Make sure to note this kind of thing in your style sheet!

What Do You Actually Say?

Sometimes, though, we don’t say the abbreviation; we say what it stands for. We all know that if we see etc., we say “et cetera” and if we see 20 lb. we say “twenty pounds.” It’s also true for some often-used acronyms. For example, if you use MS to stand for multiple sclerosis, you say it as the letters, “MS,” but if you use it to stand for manuscript, you say it as “manuscript.” So it’s an MS treatment when it’s “an MS [multiple sclerosis] treatment” and a MS treatment when it’s “a manuscript treatment.”

Oh, and here’s an * to that topic: how you refer to a symbol also governs your choice of article before it. If you’re talking about the telephone number pad, a * is “a star,” but if you’re talking about footnotes and similar typography, an * is “an asterisk.” Even Mr. Bumble was never heard to say “a asterisk.”

Batteries and Agents

There’s an extra trick to watch out for: sometimes instead of pronouncing an abbreviation as a word or saying each letter individually, or even saying what it stands for, we describe it using a word that’s not in it—such as double. That’s why you can use a AA battery (say “a double-A battery,” but don’t write it that way), and James Bond is a 00 agent (“a double-O agent,” which is extra sneaky, because 00 contains neither the word double nor the letter O)—but James Bond may (or may not) attend an AA meeting, because the short name for Alcoholics Anonymous is said as the letters.

A Historical Precedent

And, of course, there’s an historic. In English, we gradually learn that if something is weird and unexpected, it must be correct; we privilege exceptions to rules, and we scorn people who adhere to a rule when there’s a random exception (“It’s not goed, you foolish child; it’s went”). So, for those of us who pronounce the h on historic, the first time we heard (or saw) an historic, we likely assumed that it must be a special exception to the rule, perhaps signifying the momentous solemnity of the occasion.

It’s not, though. It’s just an holdover—sorry, a holdover—from a time when the fashion even in North America was to drop h at the start of a word. And that fashion held longer in cases where the first syllable was unstressed (an heroic, an hotel). But ultimately, the h came back into use in North America (and in some parts of England), and a became the article to use before all of those words. However, the belief that historic (and sometimes historical) was an exception managed to hang on, and even today you see and hear it in some quarters—but, as The Chicago Manual of Style (5.250) advises us, “The word historical and its variations cause missteps, but if the h in these words is pronounced, it takes an a {an hour-long talk at a historical society}.” And no, the n on an does not cause you to drop the h on historical any more than it does on, say, hotel. It’s always the n that gets dropped, never the following consonant (that would be an ’eird thing—sorry, a weird thing). So if you don't say “’istoric,” don’t write an historic.

A Useful Bit of Software

Most of the time, the choice of a or an isn’t a big issue. But sometimes it is. Sometimes you discover at an awkward moment that the way you say something is not the way your client or a particular reader says it. That’s especially the case when you’re working on documents with an international audience.

Unless all of your colleagues are also language professionals, you probably won’t be able to convince them to read advice like this article! So it helps to build examples into your house style. Even if the choice between a or an seems obvious to you, English is not everyone’s first language. Even for native speakers, the fact that so many of us learned an incomplete version of this rule as children means that it can be difficult to get right as adults. And that’s before the added complication of maintaining consistency between several people who might not all say everything the same.

That’s where an automated consistency checker such as PerfectIt can be useful. PerfectIt can help you to ensure consistency within a document, between documents, and even across a whole department. PerfectIt has The Chicago Manual of Style built into it for CMOS Online subscribers so it can help to ensure your entire team is correct and consistent. PerfectIt won’t ask you about every single questionable instance of a versus an—that would be excessive—but it will check key instances and remind you of the principles involved. And you can customize it further, for example to reflect the preferred pronunciation of acronyms particular to your organization.

If you don’t already have PerfectIt, it’s free to try for 14 days. Click to try it now.