The girl ___ wears green is Irish.
who
The people who celebrate wear green.
Defining
Easter is a festival. It celebrates new beginnings.
Easter is a festival that celebrates new beginnings.
The eggs that are hidden in the garden are made of chocolate.
The eggs hidden in the garden are made of chocolate. (Reduced relative clause)
The festival ___ takes place in August is very popular.
which/that
Saint Patrick’s Day, which is celebrated in March, is very popular.
Non-defining
The parade is exciting. It happens every year.
The parade which/that happens every year is exciting.
The people who live in Ireland celebrate on March 17th.
The people living in Ireland celebrate on March 17th.
That’s the musician ___ costume was amazing.
whose
The parade that starts at 10 a.m. is the best one.
Defining
The dancers are talented. They perform in the carnival.
The dancers who perform in the carnival are talented.
The parade, which was organised last year, was spectacular.
The parade, organised last year, was spectacular.
The street ___ the parade happens is very crowded.
where
Notting Hill Carnival, which attracts millions of visitors, is colourful.
Non-defining
We visited the city. The carnival takes place there.
We visited the city where the carnival takes place.
That is the house where the celebration takes place.
That is the house in which the celebration takes place. (Formal relative clause)
The man ___ son won the costume competition is very proud.
whose
The students who were wearing costumes won the prize.
Defining.
Can we omit the relative pronoun?
I met a girl. Her brother plays in a reggae band.
I met a girl whose brother plays in a reggae band.
The festival attracts many tourists. It lasts three days. It is held in London.
The festival, which is held in London and lasts three days, attracts many tourists.
or
The festival, held in London and lasting three days, attracts many tourists.