Indefinite article (a/an)
We use the indefinite article a/an for singular countable nouns:
When we mention something for the first time
– The concept of a brand is difficult to define.
When it doesn’t matter which particular person or thing we are referring to
– I bought this T-shirt in a supermarket.
Definite article (the)
We use the definite article the for singular and plural countable nouns, and with uncountable nouns:
When something has already been mentioned, so we already know which person or object is being reffered to
– My parents lived in a small house. The house was old…
When there is only one thing or person
– The actor who played James Bond in ‘Dr No’ was Sean Connery.
When there is one thing, person etc. that is especially important to the speaker
– I’ve got an appointment at the hospital.
In generalisations with singular countable nouns
– The panda is threatened with extinction for nationalities.
– Many of the English prefer coffee to tea.
With adjectives used as nouns
– She goes to a special school for the blind.
For regions, mountain ranges, oceans, seas and countries (when these refer to a collection of states or areas)
England is part of the British Isles.
For hotels, restaurants, theatres and cinemas
– We can’t possibly afford to stay at the Ritz.
We use no article (the zero article):
In generalisations with plural and uncountable nouns when we mean „all”
– I like music.
When we are reffering to the general use of an institution rather than a particular place
– He goes to school in Scotland.
– He’s been taken to hospital.
For continents, countries and cities
– Perth is in Australia.
For mountains and lakes
– Lake Vostok is permanently frozen.
For most streets (except the High Street)
– I live on North Avenue.