Relative Pronouns

 - A relative pronoun is used to connect a clause or phrase to a noun or pronoun. 

Use of the relatives pronouns:

1-Who: It can only be used to refer to people.

Ex: The driver who ran the stop sign was careless.

Explanation: "who" refers to the driver, which is a person.

2- Whom: It is used to refer to an indirect object of the verb (who is frequently used in place of whom).

Ex: This is John, whom I met the last week.

Explanation: "whom" refers to John, which is the object.

3- Whose: It is used to indicate posession, both for people and things.

Ex: That is the kid whose parents got divorced last month.

Explanation: The parents who got divorced are the parents of that specific kid.

4- Which: It is used only to refer to things. 

Ex: The house which I lived ten years burned down yesterday.

Explanation: "which" refers to the house, a thing.

5- That:  It is used to refer to people or things (usually is used instead of which who, or whom).

Ex: This is the book that everyone is talking about is very good.

Explanation: "that" refers to the book, a thing.

Ex: My friend is that guy over there.

Explanation: "that refers to the friend, aperson.

My experience:

 This topic is very to understand and basic. However, it is important to use the correct relative pronoun according to the situation, especially in essays.

(click here to watch a video about relative pronouns)