Relative Pronoun- Definition, Types, and Usage
What Are Relative Pronouns?
Relative pronouns are words that connect a clause or phrase to a noun or pronoun that came before it. They introduce relative clauses—also called adjective clauses—without starting a new sentence.
Think of them as bridge words. They link additional information to a noun while keeping your sentences clean and connected.
The most common relative pronouns in English are: who, whom, whose, which, and that.
The Five Main Types
Each relative pronoun serves a specific function. Here's the breakdown:
Who
Use who when referring to people as the subject of a relative clause.
Example: The teacher who taught me history retired last year.
Here, "who" connects to "the teacher" and acts as the subject of "taught."
Whom
Whom is the object form of "who." Use it when referring to people as the object of a verb or preposition.
Example: The candidate whom we interviewed had excellent credentials.
In informal English, most people replace "whom" with "who." That's fine in speech, but in formal writing, "whom" is still expected after prepositions.
Whose
Whose shows possession. It works for both people and things.
Example: The author whose book I read lives in Boston.
Example: The house whose roof was damaged has been repaired.
Which
Use which for animals and things. It can introduce both restrictive clauses (essential information) and non-restrictive clauses (extra information set off by commas).
Example: The car which broke down was towed away.
That
That works for people, animals, and things. It's common in restrictive clauses and often preferred in informal and spoken English.
Example: The song that won the award was written by a teenager.
That vs. Which: The Real Rule
English learners get confused here. Here's the actual distinction:
- That introduces restrictive clauses. These clauses are essential to the meaning. No commas.
- Which introduces non-restrictive clauses. These clauses add extra info that could be removed without changing the core meaning. Commas required.
Restrictive: The book that sits on the shelf is mine. (Which book? The one on the shelf. Essential info.)
Non-restrictive: The book, which sits on the shelf, is mine. (I have one book. It happens to be on the shelf. Extra info.)
In American English, this distinction is strict. In British English, "which" sometimes appears in restrictive clauses without commas. Know your audience.
Relative Pronouns vs. Relative Adverbs
Don't confuse relative pronouns with relative adverbs. Relative adverbs introduce clauses and add information about place, time, or reason.
The three relative adverbs are: where, when, and why.
Example: The town where I grew up has changed completely. (place)
Example: July is the month when vacation season starts. (time)
Example: I understand the reason why he quit. (reason)
Quick Reference Table
| Pronoun | Used For | Function | Example |
|---|---|---|---|
| Who | People | Subject | The doctor who treated me was kind. |
| Whom | People | Object | The patient whom we visited recovered. |
| Whose | People & Things | Possession | The nurse whose shift ended called me. |
| Which | Animals & Things | Subject/Object | The hospital which opened last month is huge. |
| That | People, Animals & Things | Subject/Object | The surgery that saved his life took 12 hours. |
Common Mistakes to Avoid
1. Using "which" without a comma for non-restrictive clauses.
Wrong: The report which was published yesterday shows growth.
Right: The report, which was published yesterday, shows growth.
2. Double-using relative pronouns.
Wrong: The student who he studied hard passed.
Right: The student who studied hard passed.
3. Mixing up "who" and "whom" after prepositions.
Wrong: The professor we talked to who gave the lecture.
Right: The professor whom we talked to gave the lecture.
How to Identify Relative Pronouns in Any Sentence
Here's a practical method to spot relative pronouns:
- Find the noun first. Look for the person, place, or thing being described.
- Look for the word that follows it. If a clause starts right after the noun, check what word introduced that clause.
- Ask "who, what, or which" questions. If you can replace the word with "who, which, or that" and the sentence still makes sense, you've found the relative pronoun.
Try it: The building that collapsed has been demolished.
Ask: "What building collapsed?" Answer: "That building collapsed." So "that" is your relative pronoun.
How to Use Relative Pronouns Correctly
Step 1: Identify your noun. Decide if it's a person, animal, or thing.
Step 2: Decide if the clause is essential (restrictive) or extra (non-restrictive).
Step 3: Choose the right pronoun. Use "who/whom/whose" for people. Use "which/that" for things. Use "whose" for possession.
Step 4: Add commas only for non-restrictive clauses. Skip them for restrictive ones.
Step 5: Check your sentence reads smoothly. If it sounds clunky, simplify.
The Bottom Line
Relative pronouns are straightforward tools. Five words—who, whom, whose, which, that—do most of the work. Master the restrictive vs. non-restrictive distinction and you'll avoid 90% of the errors writers make with them.
Keep it simple. Keep it clean.