The acts as a definite article, specifying a particular noun or something specific. Here are situations for using the before nouns.

  1. When the thing is already mentioned, or we know which thing we are talking about

Example

  • A man and a woman sat in front of me. The man was British, but I think the woman wasn’t.
  • ‘Where are the kids?’ ‘They’re in the garden’.
    • (=Both speakers know which kids and which garden).
  1. When the thing is made specific by some details we give to it

Example

  • I sat on the chair in the corner.
  • I saw the man who tried to rob me.
  1. When there is only one of it: the earth, the moon, the planet, the internet, the universe, the sky, the city, etc.

Example

  • I need to talk to the manager.
  • The moon looks beautiful today.
  1. When we talk about places where we commonly go: the park, the cinema, the doctor, etc.

Example

  • I’m going to the bank.
  • I found Peter at the station.
  1. Superlatives

Example

  • This is the best restaurant in town.
  1. Name of oceans, seas, rivers, continents, and canals

Example

  • I’d like to cross the Atlantic on a cruise.
  1. Countries that are plural or that include words like State, Republic, or Kingdom

Example

  • the US (the United States), the UK (the United Kingdom), the Philippines, the Netherlands, the Czech Republic.

References