Relative clauses are used to provide extra information about a person or thing mentioned in a sentence. They introduce this additional information using relative pronouns like who, which, that, where, when, and whose. Relative clauses can be defining, where the information is essential, or non-defining, where it is non-essential and separated by commas. Examples are given of sentences with defining relative clauses that identify the musician John and the train Susan missed, and a non-defining clause about tourists at Candem Market.

1. 1. Relative clauses are sentences we use to give extra information which can be
relevant or not.
2. To introduce relative clauses we use the relative pronouns:
• who (for people)
• which (for things: objects and animals)
• that (also for people and things, but in defining relative clauses)
• where (for places)
• when ( for time)
• whose (possession)
See these sentences:
1. John is the musician who plays the lead guitar for "The Rockets". (*John is
themusician. He plays the lead guitar for "The Rockets")
2. Candem Market, where tourists buy souvenirs, is in a popular area of
London. (*Candem Market is in a popular area of London. Tourists buy
souvenirs there)
In these 2 sentences the relative clauses are just after the elements they are
connected to (musician and Candem Market).
Now we will join these couples of sentences by using a relative pronoun:
 Susan missed the train. It left 10 minutes earlier (the train & It are
connected)
 Susan missed the train which left 10 minutes earlier (relative clause)
 Susan missed the train. She had to postpone a meeting (Susan & she are
connected)
 Susan, who had to postpone a meeting, missed the train (relative clause)
BE CAREFUL: It & She are replaced by the relative pronoun
DEFINING RELATIVE CLAUSES: when the information they give is
important, relevant, necessary:
• Susan missed the train which left 10 minutes earlier.
NON-DEFINING RELATIVE CLAUSES: when the information they give is
not important; you can do without it. They always go between commas ( , ... , ):
• Candem Market, where tourists buy souvenirs, is in a popular area of
London.