Today English cllas about (Relative clauses – non-defining relative clauses)

Do you know how to give extra information about someone or something using relative clauses?
Look at these examples to see how non-defining relative clauses are used.
1- Jack, who's retired now, spends a lot of time with his grandchildren.
2- We want to see the new Tom Carter film, which was released on Friday.
3-My sister, whose dog I'm looking after, is visiting a friend in Australia.

Grammar.
Read the explanation to learn more. Grammar explanation.
Relative clauses give us information about the person or thing mentioned.
Non-defining relative clauses give us extra information about someone or something. It isn't essential for understanding who or what we are talking about.
some examples to see how non-defining relative clauses are used.
1-My grandfather, who's 87, goes swimming every day.
2- The house, which was built in 1883, has just been opened to the public.
3-The award was given to Sara, whose short story impressed the judges.
Rules to use
1- We always use a relative pronoun or adverb to start a non-defining relative clause: who, which, whose, when or where (but not that). We also use commas to separate the clause from the rest of the sentence.
how non-defining relative clauses are used
A) who, which and whose
Rule 2-We can use who to talk about people, which to talk about things and whose to refer to the person or thing that something belongs to.
Some examples to see how non-defining relative clauses are used
1- Yesterday I met my new boss, who was very nice.
2- The house, which is very big, is also very cold!
3- My next-door neighbour, whose children go to school with ours, has just bought a new car.
4-After the port there is a row of fisherman's houses, whose lights can be seen from across the bay.

B)Places and times

We can use which with a preposition to talk about places and times. In these cases it's more common to use where or when instead of which and the preposition.
Some examples to see how non-defining relative clauses are used
1- City Park, which we used to go to, has been closed down.
2- City Park, where we used to go, has been closed down.
3- December, which Christmas is celebrated in, is a summer month for the southern hemisphere.
4- December, when Christmas is celebrated, is a summer month for the southern hemisphere.

However, when we use which without a preposition, we can't use where or when.

some other examples.
1-Centre Park, which we love, is always really busy on Saturdays.
2- February, which is my favourite month, lasts 29 days this year.