Relative Pronouns / Relative Clauses

Relative Pronouns are who, whom, that, which, whose, where, and when. We use relative pronouns to connect a clause or phrase to a noun​ (in the main clause) that it modifies. The clause with relative pronoun is called a relative clause (all the below underlined clauses). It functions as an independent clause.

We use who and that for people.

• My teacher has a luxury car. He is also an online freelancer.
  My teacher who/that is also an online freelancer has a luxury car.
• JK Rowling is an author. She wrote Harry Potter series.
  JK Rowling is the author who/that wrote Harry Potter series. 

We use whom for people as an object. Who and that can also be used in an informal way.

• He is the traveler. I saved him.
  He is the traveler whom I saved.

We use which and that for things.

• The film was horrible. We watched it last night.
  The film which/that we watch last night was horrible.
• I lost the pen. You lend it to me.
  I lost the pen which/that you lend to me.

We use whose for possessions.

• She's a lucky woman. Her husband is a billionaire.
  She's a lucky woman whose husband is a billionaire.
• They are the people. Their houses were burnt down a few days ago.
  They are the people whose houses were burnt down a few days ago.

We use where for places.

• This is the city. We grew up here.
  This is the city where we grew up.
• That is the park. I lost my wallet there.
  That is the park where I lost my wallet.

We use when for time.

• It was yesterday. The committee announced its winner at that time.
  It was yesterday when the committee announced its winner.