Relative Clauses: who, which, that in English

Overview

Relative clauses are parts of a sentence that give extra information about a noun. They begin with a relative pronoun -- who, which, or that -- and help you combine two ideas into one smooth sentence. Instead of saying "I have a friend. She lives in London," you can say "I have a friend who lives in London."

At the CEFR A2 level, you will focus on defining relative clauses -- clauses that identify or specify which person or thing you are talking about. These clauses are essential and cannot be removed without changing the meaning of the sentence. They are written without commas.

Mastering relative clauses will make your English sound significantly more fluent and sophisticated. They are one of the most commonly used structures in both spoken and written English, and they allow you to express complex ideas in a single, natural-sounding sentence.

How It Works

Choosing the Right Relative Pronoun

Pronoun	Used for	Example
who	People	The woman who called you is my sister.
which	Things / Animals	The book which I bought is excellent.
that	People or Things	The car that I want is too expensive.

Subject vs. Object Relative Clauses

Type	Structure	Example
Subject (pronoun = subject of clause)	noun + who/which/that + verb	The man who lives next door is friendly.
Object (pronoun = object of clause)	noun + who/which/that + subject + verb	The book that I bought is interesting.

In object relative clauses, the pronoun can often be omitted: "The book I bought is interesting."

In subject relative clauses, the pronoun cannot be omitted: "The man lives next door is friendly."

Key Rules

1. No double subject/object: Do not repeat the noun inside the clause. "The man who he lives next door" is wrong.
2. Verb agreement: The verb in the relative clause agrees with the noun it describes: "The girl who is here" / "The girls who are here."
3. That vs. which/who: In everyday English, that can replace both who and which in defining clauses. It is very common in spoken English.

Examples in Context

English	Note
The man who lives next door is a doctor.	Who for people (subject relative clause)
The book which I bought was cheap.	Which for things (object relative clause)
The car that I want is red.	That for things (interchangeable with which)
People who work hard succeed.	Who for people in general statements
The restaurant that we went to was great.	That for a place (as object)
I like the dress which she is wearing.	Which for a thing (object)
The teacher who taught me is retiring.	Who as subject of the clause
Is this the phone that you lost?	That in a question
The students who passed the exam celebrated.	Who with a plural noun
The film (that) we watched was boring.	That can be omitted (object position)

Common Mistakes

Adding an extra pronoun inside the clause

• Wrong: The man who he lives next door is friendly.
• Right: The man who lives next door is friendly.
• Why: The relative pronoun who already replaces "he." You cannot use both.

Omitting the pronoun in a subject relative clause

• Wrong: The woman works here is my friend.
• Right: The woman who works here is my friend.
• Why: You can only omit the relative pronoun when it is the object of the clause, never when it is the subject.

Using "which" for people

• Wrong: The girl which is singing is my daughter.
• Right: The girl who is singing is my daughter.
• Why: Which is for things and animals. Use who or that for people.

Wrong verb agreement

• Wrong: The people who lives here are friendly.
• Right: The people who live here are friendly.
• Why: The verb must agree with the noun the clause describes. People is plural, so use live.

Usage Notes

In American English, that is strongly preferred over which in defining relative clauses: "The house that I bought" rather than "The house which I bought." In British English, both are acceptable, though which is slightly more formal.

For people, that is common in casual speech ("The guy that I met"), but some style guides prefer who in formal writing ("The person who I met"). Both are grammatically correct.

In spoken English, object relative pronouns are almost always dropped: "The movie we saw" rather than "The movie that we saw." This sounds more natural and is perfectly correct.

Practice Tips

• Sentence combining: Take two short sentences and join them with a relative pronoun. "I met a woman. She speaks five languages." becomes "I met a woman who speaks five languages."
• Spot them in reading: When reading English texts, underline every relative clause you find. Notice whether the pronoun is a subject or object, and whether it could be omitted.
• Quiz yourself: Cover the relative pronoun and try to fill it in. This trains your instinct for choosing between who, which, and that.

Related Concepts

• Prerequisite: Subject Pronouns -- understanding pronouns is essential before learning how relative pronouns replace them in clauses
• Next steps: Relative Clauses: where, when, whose -- extends this concept with relative pronouns for places, times, and possession