Basic rules
a = indefinite article (not a specific object, one of a number of the same objects) with consonants
Gregory works in a factory.
Eric has a dog.
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?
Donata is an English teacher.
the = definite article (a specific object that both the person speaking and the listener know)
The teacher is very good, isn't he?
The car over there is fast.
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 two bedrooms.
I ate in a Vietnamese restaurant. The restaurant was not very clean.
DO NOT use an article with countries, states, counties or provinces, lakes and mountains except when the country is a collection of states such as "The United States".
My uncle lives in Cumbria near Lake Windermere.
They live in Bristol.
Use an article with bodies of water, oceans and seas.
I live on a small island in the Baltic Sea.
DO NOT use an article when you are speaking about things in general
I like Indian tea.
Simon likes reading books about linguistics.
DO NOT use an article when you are speaking about meals, places, and transport.
He has breakfast at home.
I go to university.
Magda comes to work by taxi.
