Using the

The is used before countable nouns to talk about something the listener or reader knows about.

  • I saw the moon last night.
    (There is only one moon, so we know which moon.)
  • The capital of France is Paris.
    (France has only one capital, so we know which capital.)
  • There is some milk in the fridge.
    (I only have one fridge, so we know which fridge.)
  • She is the best swimmer here today.
    (best is a superlative adjective, so we know which swimmer.)

The first time you talk about something use a or an. The next time you talk about it use the.
Compare:

  • I want to buy an umbrella.
    (There are lots of umbrellas to buy, so we don’t know which umbrella.)
    I want to buy the blue umbrella we saw yesterday.
    (We know which umbrella – the blue one – so the.)
  • There is a woman in reception.
    (We don’t know which woman because we have never seen her before.)
    The woman from the bank in reception.
    (We know which woman – the woman from the bank – so the.)
  • A man in a white t-shirt is riding an orange bike. The man is looking for a place to park the bike.
    (A man, a white t-shirt, an orange bike – first time we talk about these things.)
    (The man, the bike – we know about these things. A place – first time we talk about this thing.)
  • I was on holiday last week. The hotel was very good.
    (We say The hotel because the reader knows, or can understand, it is the hotel I stayed in on my holiday.)

Now do Using the · exercise 1.