USE OF ARTICLES (a, an, the)
What did these words originally mean?
A/AN is an old word meaning `one'
(in many European languages the ordinary word for `one' is used to translate English `a' or `an' and you can also sometimes use Cantonese `yat go' in the same way)
THE is an old word meaning `this' or `that'
These words no longer have their full original meaning but if you remember that meaning it can sometimes help you to decide which word you need to use.
A or AN?
Use A before a consonant sound
Use AN before a vowel sound
So: a banana,
a university (vowel letter but a consonant sound - /j/)
an MTR train (consonant letter but a vowel sound - /em/)
Use of A/AN
You use these words with a singular, countable noun:
when something is mentioned for the first time
E,g. There is a gorilla in the general office
when you mention one of a group of objects but do not make it clear which of them you mean
E.g. Go to the cupboard and bring me a plate
(The listener already knows about the plates in the cupboard but it does not matter which of the plates he brings)
You ALWAYS need to use A or AN with a singular countable noun unless it already has a word like the, my, this etc.showing
which person or thing is being referred to:
So: I saw a dog/the dog/your dog/ this dog (
BUT I saw dog X
Use THE when the listener or reader already knows which person or thing you are referring to:
something which has already been mentioned before.
E.g. The gorilla switched on the air-conditioner (you know about the gorilla because I mentioned...