1. Definite Article: the

The article the  is a determiner in a sentence when placed before a noun or a noun phrase. It is called a definite article as it points to a particular person or thing being mentioned in the sentence. It can be used before a singular or a plural noun, and before a countable and an uncountable noun.

We use the determiner 'the'

to refer to people or things which we know because they have already been mentioned.

Examples:

  • I recognize that man. He's the  one who is doing great magic at the marketplace.
  • Over there is a cave. There are countless bats roosting in the cave.

to refer to a person or thing when there is only one.

Examples:

  • He is  the boss  of the company producing pencils.
  • The flood occurred only in the east coast  of the country.

before superlatives, words such as first , only , etc.

Examples:

  • Peacocks have the most beautiful feathers.
  • The first  runner to cross the finishing line was a skinny man.
  • This duckling is the only  pet I have.

before adjectives that act as nouns.  

Examples:

  • Sometimes I hate myself for dreaming the impossible .
  • They buried the dead  wherever they found them.

before a singular noun that is representative of a group of similar people or things.

Examples:

  • A large and flightless bird, the dodo  is now extinct.
  • The satellite  has many uses, the most important of which I think is the transmission of information.  

before proper nouns.

Examples:

  • The  Robinsons  are the latest members of the ghost-hunting club.
  • The  Niagara Falls  is the largest waterfall in the world.