Relative Pronouns :
Relative pronouns are words ( who / that / which / whose / whom / when / where / why ) used to connect sentences joining their ideas. The part of the sentence containing the relative pronouns is the relative clause and it is subordinated to the main clause.
There are two types of relative clauses: defining and non - defining relative clauses:
These clauses state essential information to the understanding of the main clause.
That's the man. He fixes pipes.
That's the man who fixes pipes ( " Who fixes pipes " explains what man we are talking about )
Have you read the book which I recommended ? ( " Which I recommend " explains what book I am talking about )
A.1 ) Relative pronouns as subjects : ( substitute the subject of the relative clause )
Who / that - for people.
Which / that - for things.
. Brian is the boy who / that lives next door.
. I've read the book which / that is the best selling book of the year .
A.2 ) Relative pronouns as objects: ( substitute the object, the relative clause has it own subject )
Who / whom / that / (omission ) - for people.
Which / that / (omission ) - for things.
. Brian is the boy who / whom / that / (omission) I need to talk to.
. I've read the book which /that / (omission) you recommended.
obs: Omission means you don't need to use any relative pronouns.
Whom is more formal than who and can only be used as object.
The function object means that after the relative pronoun the rest of the sentence has subject, verb and complement.
A.3 ) Relative pronouns describing possession.
Whose - people / things ( substitute a possessive adjective )
. Kelly works in a shop. Its owner is Mr. Gonzalez
Kelly works in a shop whose owner is Mr. Gonzalez.
. I know a woman. Her husband is an Air Force pilot.
I know a woman whose husband is an Air Force pilot.
A.4 ) Relative pronoun describing places:
That's the restaurant where I work ( after where in a relative clause there is a subject as well as a verb )
A.5 ) Relative pronoun describing time:
April is the month when I usually travel to the south ( After when in a relative clause there's always a subject as well as a verb )
A.6 ) Relative pronoun describing reason:
I don't know why we need it ( = the reason )
( after why we also find a subject as well as a verb in this kind of clause )
A.7 ) Relative pronoun what ( it refers to the second clause , not the antecedent one )
. They didn't understand what I said.
B) Non - defining ,
These clauses state extra information which is not relevant to the undersranding of the main clause. They come between commas ( , , ) or a comma and a period ( , . )
That man is George, who lives in Columbus Av.
Outback, which is a Steakhouse restaurant, is always busy.
( " who lives in Columbus Av. " and " which is a steakhouse restaurant " are pieces of extra information and they don't interfere in the understanding of the main clauses )
B.1 ) Relative pronouns as subjects :
Who - for people.
Which - for things.
( That is not used in non - defining clauses )
I love talking to Gina, who has been my friend since kindergarten.
Bob, who graduated last June, has just gotten a job with Boston Bank.
Rio is a place full of beautiful beaches, which attract people from all different walks of life.
B.2 ) Relative pronouns as objects :
Who / whom - for people.
Which - for things.
( Again , that as well as omission are not permitted in non - defining clauses )
. Mrs. Silva, who / whom everybody admires, has donated a huge amount of money to another charity program.
. I loved the latest Madonna's album, which is already number 1 on the charts.
B.3 ) Other relative pronouns in non-defining clauses.
Whose - possession ( people / things )
Where - places.
When - time.
In both defining and non - defining clauses we use only whom , which or whose after prepositions. Whom if we refer to people , which if we refer to things and whose if we describe possessions.
. Tim is one of whom the board is going to award with a special medal.
. Anita, to whom I talked on the phone , said she can't come to the dinner.
. Luckily we had a GPS, without which we would have been definitely lost.
. We get along really well whith the Bransons, at whose place we spent a wonderful New Year's Eve.