Defining and Non-Defining Relative Clauses

Relative clauses function like adjectives because they describe or add information about a noun or noun phrase.  They come immediately after the noun they describe.  Relative clauses usually begin with relative pronouns such as which, that, when, where, who, how, why.  These words give you a clue that a relative clause is coming up.  

Here's a chart to help you remember characteristics of defining and non-defining relative clauses:

 

              

  Relative Clauses                      

Defining

Non-Defining

  • Gives essential information about the noun it describes
  • Gives optional (non-essential) information about the noun it describes
  • *that, when, where, who, why, how
  • that (cannot use “that”)
  • which, when, where, who, why, how

For example:

“The downtown area has dozens of shops that sell the latest fashions.

For example:

“Our friend Tom, who lives here, will take us sightseeing.”

Not just any shops; but specifically shops that sell the latest fashions.

The clause ‘who lives here’ is optional information about Tom.

  • No commas
  • Commas

              

Sentences:

 
  • We are going on a train that will take us to the Highlands(Defining)
  • The train, which will take us to the Highlands, is called the West Highland Line.  (Non-defining)

 
  • The painting that was hanging in the hallway was stolen.  (Defining) Specifically, the painting hanging in the hallway only was stolen; no paintings in the living room, bedroom, etc.
  • The painting, which was hanging in the hallway, was stolen.  (Non-defining).   This sentence gives extra information about the painting.  It was hanging in the hallway, but we don't know if there were other paintings stolen as well.

 
  • The man who sold us the car is waiting outside.  (Defining)    If we eliminate this clause, it changes the entire meaning: "The man is waiting outside."  ---it could be any man.    However, the clause restricts the meaning to a specific man → specifically the man who sold us the car.

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