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X-ray? Is it a or an X-ray?

As we have now learnt, a and an are examples of determiners, one of a group of words that makes it clear what the noun is that follows.


In this case, a and an are those determiners that are called articles. But to be more precise, and an are known as indefinite articles.


But we will not worry about that bit of extra information at this stage. We will come back to that a little later on this page.

Here is how a and an work.


A/an can mean one of something, one of possibly many of the same things, for example:

A pen/one pen. A nice hat. There is a pen on the table. Have you got a book? I would like an egg for breakfast.


Remember that a/an is only used with countable nouns. We do not usually say an oxygen, a water, a salt, etc.


It is important to remember that we do not use a/an to mean more than one individual thing. We say a car, but for more than one we usually say cars (NOT a cars). We can, of course, use a numeral or a quantifier (two other kinds of determiners) and not a/an as this tells us the number of cars: two cars, ten cars, several cars, etc. A/an only tells us about one.

A/an is used when we are talking about something for the first time:


There is a restaurant next to the beach. I had an omelette for lunch. We're going to buy a new house


A/an is used for those nouns that are not clear, specific or particular:


Warsaw is a city. (there are many cities – Warsaw is one of them)
It’s a nice day today. (there are many nice days – today is one of them)

I need to buy a new dress. (there are many possible dresses the speaker can buy)

Have you got an idea how this new computer app works? (I don't know if you have any ideas or knowledge on how to use this particular computer application, and that is why I am asking you)

As you may have seen, our pen, restaurant and omelette examples can follow the same rule:


There is a restaurant next to the beach. (there are many nice restaurants, and one of them is next to the beach) NOTE: We will explain the use of 'the' in more detail later, but in summary, the means one specific beach, not one of many possible beaches that are next to this particular restaurant.

I had an omelette for lunch. (there are many omelettes that can be prepared and you had one of them for lunch)
There is a pen on the table. (there are many pens, and there is one on this particular table).


Every time we use a or an, we are talking about the idea of one thing that is one of possibly many of the same things, but we are not told precisely or in a definite way what, where, when, how, which, etc, these things are. In other words, a and an are known as indefinite articles.



e) A QUICK CHECK (5 minutes)

Do you know what are consonants and what are vowels?




Consonants are the letters b,c,d,f,g,h,j,k,l,m,n,p,q,r,s,t,v,w,x,y, and z. It is important to note that in English, the letter y is considered to be a consonant, and written as such, particularly when it is the first letter of the noun: youthful, yacht, yesterday, etc.


Vowels are the letters a,e,i,o,u. The letter is not generally considered as a vowel, but when written it is sometimes used as such, usually within nouns and not as the first letter: sky, flying, crystal, etc.


One problem is that students are often told that when the noun (or noun phrase) that follows begins with a consonant letter, then the indefinite article should be a. If it begins with a vowel letter, then it is an that goes before the noun. But this is not always true.


Try the little exercise below. (It is taken from Typical Errors in English)

f) A QUICK CHECK (8 minutes)

Fill in the missing indefinite articles a or an in the poem below.

As I walked along ____ one-way street, ____ honest man walked on.

He said he had ____ MBA, but… ____ hour later, gone

He’s from ____ university, ____ European one,

So I bought ____ one-way ticket to ____ hotel in Lon – don.

There was ____ historian there, ____ MD with ____ X-ray,

He said, ‘I work in ____ unit, it’s me you saw today!”

He said ____ universal truth, and boy it made me howl!

‘Your articles are all mixed up with consonants and vowels!’


You may well be surprised to learn that the answers are probably all the opposite to what you expected! There is not a rule that says a single, countable noun, when it is introduced for the first time, should have the article before the noun if that noun begins with a consonant, or if it begins with a vowel letter then it should be preceded with an. No. There is no such rule!

So what is the rule?

As we have already mentioned, a, e, i, o, u are vowels, but when spoken, these can be used differently. So we will now go through some examples in my lovely poem:


An one-way street. What do I actually say? A won-way street or an ON- way street?

It is the first example, of course. Because when speaking, I make the first syllable sound a consonant sound. I actually say WON, not ON, so I use a, not an. A one (pronounced won) -way street.


An honest man walked on. (the 'h' sound is not pronounced, so we say ONEST)

An MBA. (We pronounce the letter M as EM, which of course begins with a vowel letter, and so it is a vowel sound).

An hour later, gone (Perhaps the best example is this word for 60 minutes. What do I actually say? Our or hower? I say our without saying the ‘h’ before it. That makes it a vowel sound at the beginning of the word, and so I use an

A university. (We pronounce the letter U as 'You', and as y is the first letter sound of the noun university, and in this context it is being used as a consonant, we use a)

A European one. (European is pronounced your-o-pean, and as the first letter sound is 'y', so it is used as a consonant)

A one-way ticket. (Same rule as 'one-way street')

A hotel in Lon – don. (The H is sounded and is written this way, but native speakers often drop 'h' to say 'an otel', and some even choose to write it as an hotel. I would not recommend it in a test.)

A historian (Same as 'hotel')

An MD (same as 'MBA')

An X-ray (X is pronounced Eks, and so is a vowel sound)

A unit (same as 'university')

A universal truth (same as 'unit' and 'university')


So those are the basics of the indefinite article. Next up, the definite article – the.

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