Articles cause all manner of problems when learning English. It’s easy to understand why, too, because although many languages also use articles, no two languages use them in exactly the same way. And then, of course, there are many languages that do not use articles at all.
So, here is all you need to know about using indefinite articles in English.
The difference between ‘a’ and ‘an’
The first thing to establish is exactly what is the difference between ‘a’ and ‘an’ because there are some misconceptions about this.
The first thing to say is that ‘a’ and ‘an’ represent exactly the same thing, meaning that they are used in the same situations.
The decision to use ‘a’ or ‘an’ only comes with what the next word is, be that the noun or adjective that is following the article.
And contrary to popular belief, it is not decided on spelling, but on pronunciation.
‘A’ is used when the following word begins with a consonant sound. ‘An’ is used when the next word begins with a vowel sound. In most cases this is self-evident, except:
A university (not ‘an’). University begins with a ‘y’ sound, which is a consonant.
A European country (not ‘an’. Again, European begins with a ‘y’ sound.
An hour (not ‘a’). Hour begins with a silent ‘h’, so is, therefore, a vowel sound.
An honest person (not ‘a’). Again, the ‘h’ is silent.
A one-legged man (not ‘an’). One begins with a ‘w’ sound, which is a consonant.
It is therefore important to remember that using ‘a’ or ‘an’ depends on sound, not spelling.
It is important to note that, when speaking, it should be easy to identify when to use these articles as the sounds should connect easily, which is exactly why the rule exists. ‘An’ + consonant sound, or ‘a’ + vowel sound will mean gymnastics for your mouth!
Where and when to use indefinite articles
So, when should I use an indefinite article in English?
Indefinite articles are used with singular, countable nouns, when you are only providing an example of that thing, or when you are introducing that thing for the first time.
Here are examples of both of those situations:
I have always wanted a dog. I think it would be fun. (an example of something, not specific)
I have a dog. His name is Benji. (You are introducing your dog into the conversation for the first time).
Contrasting the indefinite articles with the definite article ‘the’
‘The’, as a definite article, is used to introduce something specific, or something unique. Here are examples:
The dog that lives next door to me is very big. (a specific dog that you are referencing)
Paris is the capital of France. (it is unique in that it is the only capital)
The sun is shining today. (there is only one sun)
Substituting ‘a’ or ‘an’ in any of the examples above would mean that you are talking about one of many. Here are some examples:
A dog that lives next door to me is very big. (there is more than one dog that lives next door).
Paris is a capital of France. (if France had more than one capital, which is doesn’t. You could say ‘Paris is a city in France’, which is, of course, true!)
A sun is shining today. (this just sounds ridiculous, as there is only one sun)
Failing to use any article with these single, countable nouns is always a mistake in English.