Relative Pronouns : Rules and Examples

Here is a complete and easy-to-understand guide for students preparing for school exams and competitive exams.

1. What is a Relative Pronoun?

A relative pronoun is a word that connects two sentences by referring back to a noun mentioned earlier in the sentence. The noun that it refers to is called the antecedent. Relative pronouns help us join two short sentences into one longer, smoother sentence without repeating the noun.

Example:
This is the boy. The boy won the race.
Using a relative pronoun, we can join these two sentences as:
This is the boy who won the race.

Here, “who” is the relative pronoun. It refers back to “boy” and joins the two sentences together.

2. List of Relative Pronouns

Relative Pronoun	Used For	Example
Who	Person (as subject)	The teacher who taught us is very kind.
Whom	Person (as object)	The man whom you met is my uncle.
Whose	Possession (person or thing)	The girl whose bag is red sits here.
Which	Things, animals	This is the book which I bought yesterday.
That	Person, thing, animal (defining clauses only)	The car that I drive is old.

Simple Trick: “Who” and “whom” are for people. “Which” is for things and animals. “Whose” shows ownership. “That” can be used for people, things, and animals, but only in certain situations explained below.

3. Detailed Rules for Each Relative Pronoun

3.1 WHO

• Used only for persons.
• Used as the subject of the relative clause (it performs the action).

The doctor who treated me was very patient.
I know a girl who can speak five languages.

3.2 WHOM

• Used only for persons.
• Used as the object of the relative clause (action is done to this person).
• In spoken and informal English, “who” is often used instead of “whom”. In formal writing and exams, “whom” is correct when it is the object.

The man whom we met yesterday is a famous singer.
Correct (formal): The person whom I trust most is my mother.

How to decide who vs whom: Replace the clause with “he/she” or “him/her”. If “he/she” fits, use who. If “him/her” fits, use whom.
Example: “___ helped me” → He helped me → use who.
Example: “I met ___” → I met him → use whom.

3.3 WHOSE

• Shows possession or belonging.
• Used for both persons and things (not just persons).

This is the student whose project won the prize.
I saw a house whose roof was painted blue.

3.4 WHICH

• Used for animals and things (never for persons).
• Can be used in both defining and non-defining clauses (explained in section 4).

The mobile phone which I bought last week stopped working.
The dog which barked all night belongs to my neighbour.

3.5 THAT

• Can be used for persons, animals, and things.
• Used only in defining (restrictive) relative clauses — clauses that give essential information.
• Cannot be used after a comma, and cannot be used in non-defining clauses.
• Must be used (instead of who/which) after superlatives, “all”, “only”, “the same”, and words like “everything”, “nothing”, “something”, “anybody”.

This is the best film that I have ever watched.
All that glitters is not gold.
There is nothing that can stop him now.

4. Defining vs Non-Defining Relative Clauses

This is one of the most important rules in the topic of relative pronouns.

Type	Meaning	Commas Used?	Can use “that”?	Example
Defining (Restrictive)	Gives essential information; sentence is incomplete without it	No commas	Yes	The teacher who/that teaches us Maths is strict.
Non-Defining (Non-Restrictive)	Gives extra, non-essential information; sentence makes sense without it	Commas used	No (cannot use “that”)	Mr. Sharma, who teaches us Maths, is strict.

Compare these two sentences:

Students who work hard always succeed. (Defining — tells us which students; no commas)
My brother, who works hard, always succeeds. (Non-defining — extra detail about “my brother”; commas used)

Remember: “That” is never used in a non-defining clause.
Wrong: My father, that is a doctor, lives in Jaipur.
Correct: My father, who is a doctor, lives in Jaipur.

5. Omission of the Relative Pronoun

When the relative pronoun is the object of a defining clause, it can often be dropped completely.

The book which I bought is interesting. → The book I bought is interesting.
The man whom you met is my teacher. → The man you met is my teacher.

However, the relative pronoun cannot be dropped when it is the subject of the clause.

Wrong: The boy won the race is my friend.
Correct: The boy who won the race is my friend.

6. Relative Pronouns With Prepositions

In formal English, the preposition is placed before the relative pronoun (whom/which). In informal English, the preposition is placed at the end of the sentence.

Formal	Informal
This is the person to whom I gave the letter.	This is the person I gave the letter to.
The house in which he lives is old.	The house he lives in is old.

7. Relative Adverbs (Often Studied Along With Relative Pronouns)

Although not technically pronouns, “where”, “when”, and “why” work in a similar way and are usually taught together with this topic.

Relative Adverb	Used For	Example
Where	Place	This is the school where I studied.
When	Time	I remember the day when we first met.
Why	Reason	Tell me the reason why you were absent.

8. Common Mistakes Students Make

Incorrect	Correct	Reason
The girl which sings well is my sister.	The girl who sings well is my sister.	“Which” cannot be used for persons
This is the pen who I lost.	This is the pen which/that I lost.	“Who” cannot be used for things
He is the boy who’s bicycle is new.	He is the boy whose bicycle is new.	“Who’s” means “who is”; possession needs “whose”
Ram, that is my friend, is a topper.	Ram, who is my friend, is a topper.	“That” is not used in non-defining clauses
This is the best book that which I have read.	This is the best book that I have read.	Only one relative pronoun is needed

9. Quick Summary Chart

Pronoun	Person	Thing/Animal	Subject	Object	Possession
Who	Yes	No	Yes	No	No
Whom	Yes	No	No	Yes	No
Whose	Yes	Yes	No	No	Yes
Which	No	Yes	Yes	Yes	No
That	Yes	Yes	Yes	Yes	No

10. Practice Exercise

Fill in the blanks with the correct relative pronoun (who, whom, whose, which, that):

1. This is the house ______ I was born.
2. The boy ______ pen you took is my classmate.
3. She is the only person ______ I can trust.
4. The movie ______ we watched last night was boring.
5. The man ______ you saw at the gate is our new watchman.

Answers: 1. where (or in which)   2. whose   3. that/whom   4. which/that   5. whom/who

11. Conclusion

Relative pronouns make our sentences shorter, smoother, and more connected. The key is to remember who is for persons, which is for things and animals, whose shows possession, and that can replace who or which in defining clauses. With regular practice using the tables and examples above, this topic becomes very easy to master for both school exams and competitive exams.