We use the… when there is only one of something:
* What is the longest river in the world? (there is only one longest river)
* The earth goes round the sun and the moon goes round the earth.
* I’m going away at the end of this month.
Don’t forget the:
* Paris is the capital of France. (not ‘Paris is capital of…’)
But we use a/an to say what kind of thing something is (see Unit 70C). Compare the and a:
* The sun is a star. (= one of many stars)
* The hotel we stayed at was a very nice hotel.
We say: the sky the sea the ground the country the environment:
* We looked up at all the stars in the sky. (not ‘in sky’)
* Would you rather live in a town or in the country?
* We must do more to protect the environment. (= the natural world around us)
Note that we say space (without ‘the’) when we mean ‘space in the universe’:
* There are millions of stars in space. (not ‘in the space’)
but * I tried to park my car but the space was too small.
We use the before same (the same):
* Your pullover is the same colour as mine. (not ‘is same colour’)
* These two photographs are the same. (not ‘are same’)
We say: (go to) the cinema, the theatre:
* I often go to the cinema but I haven’t been to the theatre for ages.
When we say the cinema/the theatre, we do not necessarily mean one particular cinema or theatre.
We usually say the radio, but television (without ‘the’):
* I often listen to the radio.
* We heard the news on the radio.
* I often watch television.
* We watched the news on television.
but * Can you turn off the television, please? (= the television set)
* There isn’t a theatre in this town.
* I’m going to buy a new radio/television (set).
Breakfast lunch dinner
We do not normally use the with the names of meals (breakfast, lunch etc.):
* What did you have for breakfast?
* We had lunch in a very nice restaurant.
* What time is dinner?
But we use a if there is an adjective before breakfast, lunch etc.:
We had a very nice lunch. (not ‘we had very nice lunch’)
Platform 5 Room 126 etc.
We do not use ‘the’ before noun + number. For example, we say:
* Our train leaves from Platform 5. (not ‘the Platform 5’)
* (in a shop) Have you got these shoes in size 43? (not ‘the size 43’)
In the same way, we say: Room 126 (in a hotel) page 29 (of a book) Section A etc.