Always use ‘an’ before a vowel (… except when you don’t)

We all know the rule: use ‘an’ before words that start with a vowel. But is that really the rule? Discover when you should use ‘a’ and ‘an’.

‘A’ and ‘an’ are indefinite articles, as they refer to things in general (a puppy, an orange), rather than definite objects (e.g. the ball, the cow).

One of the first things we pick up when learning English (whether as a first or second language) is not to say ‘a egg’ or ‘a owl’, but rather ‘an egg’ or ‘an owl’. The basic rule of thumb we’re taught is to use ‘an’ before a vowel, ‘a’ before a consonant.

But is that really the case? Not really. To be more precise, the rule is (almost all the time!) to use ‘an’ before vowel sounds, and ‘a’ before consonant sounds. Let’s look at some examples.

‘a’ before a vowel

When the pronunciation of the vowel begins with a non-vowel sound, use ‘a’ rather than ‘an’.

Some examples:

• a unicorn (pronounced ‘you-ni-corn’)
• a UX approach (pronounced ‘you eks’)
• a ewe (pronounced ‘you’)
• a once-in-a-lifetime opportunity (pronounced ‘wunce’)

‘an’ before a consonant

When a consonant is pronounced with a vowel sound, use ‘an’ rather than ‘a’.

Some examples:

• an hourly chime (pronounced ‘ow-erly’)
• an LOL gif (pronounced ‘el oh el’)
• an ‘m’, an ‘n’ (pronounced ’em’, ‘en’
• an NBL match (pronounced ‘en bee el’)
• an SOS message (pronounced ‘ess oh ess’)
• an Yves Saint Laurent suit (pronounced ‘eev’ (but ‘a YSL suit’ (pronounced ‘why ess ell’))

Words beginning with ‘h’

‘a hotel’ or ‘an hotel’?

The word ‘hotel’ originates from the French ‘hôtel’, which is pronounced with a silent ‘h’, therefore beginning with a vowel sound. ‘Hotel’ used to be pronounced in English in a similar way to French, so people tended to precede it with ‘an’.

Over time, more and more people aspirated the ‘h’, and the correct approach nowadays is to say ‘a hotel’, pronouncing the consonant ‘h’.

‘a historic occasion’ or ‘an historic occasion’?

So, now we’ve got that sorted, here’s a potential spanner in the works! Some style guides state that if the stress of a word beginning with ‘h’ falls on the second syllable, we should use ‘an’, not ‘a’.

For example, in the word ‘historic’, the second syllable ‘tor’ is stressed, so certain styles would insist on ‘an historic event’. The reason given is that the stressed second syllable means the initial ‘h’ is barely pronounced.

However, many style guides now prefer ‘a historic’, including Chicago, AP, Oxford Style Guide (Hart’s Rules) and more. If you adhere to a style guide, check it for preference. If you’re writing (or speaking!) without a style guide, use whichever version comes naturally to you.

Final thoughts

English is my first language, yet before I wrote this blog post, you probably would have heard me telling people that ‘an’ is used in place of ‘a’ before a vowel. You did too? Just tweak the rule to ‘vowel sound’ instead of ‘vowel’, and you’re sorted! Ah, except for the second-syllable rule for words beginning with ‘h’. Whoever said English was easy?

If you need a hand applying these tricky grammatical rules to your book, website or other text you’re working on, I can help! As an editor and proofreader, I offer a variety of services to help you polish that prose. Get in touch to find out how I can help!