Learn about using defining relative clauses.

Practice: defining relative clauses with/without the relative pronoun

Look at the examples below. They are all correct, but we can sometimes remove the words who or that (or which) without changing the meaning of the sentence. 

Click 'yes' if you think who / that is necessary in this sentence.

Click 'no' if you think we don't need who / that.

Yes No  
I have a brother who is a doctor.
I live in a house that has six bedrooms.
I'm reading a book that I don't understand.
That's the dog that bit me.
I gave the money that I found to the police.
The chair that I sat on was broken.
The man who you met yesterday is very rich.
I shouted at the children who were playing in the garden.
I laughed at the joke that he told me.
I didn't understand the grammar that we studied yesterday.