Article A, An, The

Here are the rules for when to use "A, An or The":

·         a = indefinite article (not a specific object, one of a number of the same objects) with consonants
She has a dog.       
I work in a factory.

·         an = indefinite article (not a specific object, one of a number of the same objects) with vowels (a,e,i,o,u)
Can I have an apple?        
She is an English teacher.

·         the = definite article (a specific object that both the person speaking and the listener know)
The car over there is fast.  
The teacher is very good, isn't he?

·         The first time you speak of something use "a or an", the next time you repeat that object use "the". 
I live in a house. The house is quite old and has four bedrooms.
I ate in a Chinese restaurant. The restaurant was very good.