Pronouns are words that take the place of a noun. Pronouns can do anything that a noun can do. For example, they can be subjects or objects of a verb.There are many different types of pronouns. This article focusses on relative pronouns.
Relative pronouns signal the beginning of an adjective clause (a dependent clause that modifies a noun). The three most common relative pronouns are who, which and that.
Who is used primarily for people:
The musician who wrote this song is Canadian.
Which is used for things or animals.
Jason bought our hybrid car, which will help him save on gas.
Bridget visited Stanley Park with her dog, which likes to chase squirrels.
That can be used for people, things or animals.
The musician that won the award is Canadian.
The car that Jason bought runs on electricity and gas.
The dog that chased the squirrels belongs to Bridget.
Yes, these two pronouns have different uses.
That indicates a clause essential to the meaning of the sentence:
Which introduces a clause that gives secondary, non-essential information:
That and which do not change. But the relative pronoun who often causes problems because it has three forms:
The key to distinguishing between these forms (especially between who and whom) is to see what the pronoun is doing in its own clause:
Subject form: The woman who just boarded the plane is a famous singer.
The dependent clause is who just boarded the plane, and the verb in this clause is boarded. Who is the subject of the verb boarded, so the pronoun needs to be in the subject form.
Object form: The cousin whom we met at the family reunion is coming to visit.
The dependent clause is whom we met at the family reunion. The verb in this clause is met, and the subject of the verb is we. Since there is already a subject, the relative pronoun cannot be the subject. In fact, whom is the object of the verb met (we met whom?). Therefore, the pronoun must be in the object form.
Possessive form: The people whose names are drawn win a trip to Vancouver.
The dependent clause is whose names are drawn. The verb in this clause is are drawn, and the subject is names. The names belong to the people, so we use whose in front of names to show possession.