The definite article: the
We use the definite article the:
When the person or thing referred to is unique
– The sun came out and soon we were dry.
– The President is giving a speech tonight.
– The London Marathon, the Olympic Games.
To talk about specific things when the context makes it clear what we are reffering to
– Your shoes are in the cupboard.
– Your dinner’s in the fridge.
To talk about previously mentioned things
– A man and a woman walked into the room. The man was wearing sunglasses.
– He’s the bravest person in the team.
To talk about a generic class of things
– The bycicle was invented about 200 years ago.
– The tiger is in danger of becoming extinct.
With oceans, seas, rivers and deserts
– He’s sailed across the Atlantic and the Pacific.
– We went by canoe up the Orinoco.
– She said she’d driven across the Sahara.
With plural mountain ranges and island groups
– Are the Andes as high as the Himalayas?
– The British Isles include the Isle of Wight and the Isle of Man.
With continents and countries whose name includes a common noun
– He’s from the Czech Republic, but he’s living in the United States.
– There is a range of mountains in the north.
With hotels, cinemas, theatres
– They had afternoon tea at the Ritz.
– That new Polish film is on at the Odeon.
– The Times, The Guardian, The Independent.
With national groups
– The English are a mixed race.
The indefinite article: a/an
Use the indefinite article a/an:
With (singular) jobs, etc.
– She’s an architect.
– Is your sister a football fan, too?
With singular countable nouns (mentioned for the first time or when it doesn’t matter which one)
– I’d like a sandwich and a glass of orange juice.
– What you need is a rest.
With these numbers: 100, 1.000, 1.000.000
– There were over a hundred people at the wedding.
– He made a million dollars in one year.
In exclamations about singular countable nuns
– What an amazing view!