GRAMMAR GUIDE

English Grammar: Relative Clauses

Relative clauses are the backbone of complex English sentences. This guide covers every type — from basic defining clauses to the formal fronted-preposition structures used in IELTS writing and academic papers — with real examples for each.

48 items · 6 topics

Defining Relative Clauses

"the man who called"

identifies which man — the one who made the call

"The man who called yesterday left a message for you."

Defining Relative Clauses

"the book that I read"

specifies which book — the one I read

"The book that I read last summer changed my perspective completely."

Defining Relative Clauses

"the house where I grew up"

identifies the specific place — my childhood home

"The house where I grew up has now been converted into flats."

Defining Relative Clauses

"the reason why she left"

specifies the particular reason for her departure

"Nobody knows the reason why she left so suddenly."

Defining Relative Clauses

"the car which broke down"

identifies the specific car — the one that stopped working

"The car which broke down on the motorway belongs to my uncle."

Defining Relative Clauses

"people whose jobs are at risk"

identifies the group — those with endangered employment

"People whose jobs are at risk often experience high levels of stress."

Defining Relative Clauses

"the day when we met"

specifies the exact day our meeting occurred

"I will never forget the day when we met for the first time."

Defining Relative Clauses

"a device that saves time"

identifies the category — devices with a time-saving function

"A device that saves time is invaluable in a busy office environment."

Non-Defining Relative Clauses

"my sister, who lives in Rome"

extra fact about my sister — her location is Rome

"My sister, who lives in Rome, is visiting us next month."

Non-Defining Relative Clauses

"the Eiffel Tower, which was built in 1889"

additional historical detail about the Eiffel Tower

"The Eiffel Tower, which was built in 1889, attracts millions of visitors."

Non-Defining Relative Clauses

"Professor Chen, whose research is renowned"

adds a detail about Professor Chen — her research fame

"Professor Chen, whose research is renowned worldwide, will give the keynote."

Non-Defining Relative Clauses

"last Friday, when the storm hit"

provides context about last Friday — the storm occurred then

"We lost power last Friday, when the storm hit the coastal region."

Non-Defining Relative Clauses

"the contract, which both parties signed"

adds information about the contract — it was mutually signed

"The contract, which both parties signed, takes effect immediately."

Non-Defining Relative Clauses

"New Zealand, where the film was shot"

gives the filming location of a previously named film

"The movie was filmed in New Zealand, where the scenery is breathtaking."

Non-Defining Relative Clauses

"her grandfather, who fought in the war"

extra biographical detail about her grandfather

"She always admired her grandfather, who fought in the war bravely."

Non-Defining Relative Clauses

"the decision, which surprised everyone"

adds a reaction detail to an already-named decision

"They cancelled the project, which surprised everyone on the team."

Relative Pronouns: Who, Whom, Whose

"the student who passed"

"who" = subject — the student performed the action

"The student who passed the exam celebrated with her friends."

Relative Pronouns: Who, Whom, Whose

"the teacher whom we admire"

"whom" = object of admire — formal, correct usage

"The teacher whom we admire most retired last year after thirty years."

Relative Pronouns: Who, Whom, Whose

"the author whose novel won"

"whose" = the author's novel — shows possession

"The author whose novel won the Booker Prize gave a moving speech."

Relative Pronouns: Who, Whom, Whose

"the child who is crying"

"who" identifies the specific child currently crying

"Please comfort the child who is crying near the entrance."

Relative Pronouns: Who, Whom, Whose

"the colleague with whom I work"

formal "whom" after preposition — the person I work with

"The colleague with whom I work most closely is transferring to Berlin."

Relative Pronouns: Who, Whom, Whose

"a country whose culture is rich"

"whose" shows the country's possession of a rich culture

"France is a country whose culture and cuisine are known worldwide."

Relative Pronouns: Who, Whom, Whose

"anyone who disagrees"

"who" refers to any person in the disagreeing group

"Anyone who disagrees with the policy should raise the issue formally."

Relative Pronouns: Who, Whom, Whose

"the director to whom we reported"

formal "whom" after preposition — our reporting line

"The director to whom we reported has now been promoted to CEO."

Relative Pronouns: Which & That

"the report that was submitted"

"that" in a defining clause — the specific submitted report

"Please review the report that was submitted on Friday afternoon."

Relative Pronouns: Which & That

"the app which tracks spending"

"which" defines the app by its function — spending tracker

"The app which tracks spending has over ten million active users."

Relative Pronouns: Which & That

"something that worries me"

"that" after indefinite pronoun — identifies the concern

"There is something that worries me about this financial projection."

Relative Pronouns: Which & That

"the update, which fixed the bug"

"which" in non-defining clause — extra info about the update

"We installed the update, which fixed the bug causing data loss."

Relative Pronouns: Which & That

"everything that can go wrong"

"that" after "everything" — refers to all possible problems

"Murphy's Law says that everything that can go wrong will go wrong."

Relative Pronouns: Which & That

"the bridge which connects them"

"which" defines the bridge by its connecting function

"The bridge which connects the two islands was built in 2005."

Relative Pronouns: Which & That

"the only solution that works"

"that" after superlative/restrictive "only" — the sole effective option

"Patience is the only solution that works in this situation."

Relative Pronouns: Which & That

"the data, which was encrypted"

"which" non-defining — adds the encryption detail to known data

"They recovered the data, which was encrypted and required a special key."

Reduced Relative Clauses

"the woman standing by the door"

reduced from "who is standing" — active present participle

"The woman standing by the door is our new department head."

Reduced Relative Clauses

"documents required for the visa"

reduced from "that are required" — passive past participle

"Make sure you have all documents required for the visa application."

Reduced Relative Clauses

"the student sitting next to me"

reduced from "who is sitting" — active present participle

"The student sitting next to me kept asking me helpful questions."

Reduced Relative Clauses

"the theory proposed by Einstein"

reduced from "that was proposed" — passive attribution

"The theory proposed by Einstein revolutionised modern physics."

Reduced Relative Clauses

"anyone wishing to enrol"

reduced from "who wishes" — active present participle for condition

"Anyone wishing to enrol must submit the application by Friday."

Reduced Relative Clauses

"the package delivered yesterday"

reduced from "that was delivered" — passive with time marker

"The package delivered yesterday contained fragile medical equipment."

Reduced Relative Clauses

"the bridge being constructed"

reduced from "that is being constructed" — passive continuous

"The bridge being constructed will cut commuting time in half."

Reduced Relative Clauses

"the files stored on the server"

reduced from "that are stored" — passive location

"Please back up all the files stored on the server before the update."

Advanced & Academic Usage

"the context in which it arose"

preposition fronted before "which" — formal academic style

"We must consider the historical context in which the conflict arose."

Advanced & Academic Usage

"by which point the damage was done"

"by which point" = by that time — sequential discourse marker

"They waited too long, by which point the damage was already done."

Advanced & Academic Usage

"a phenomenon whereby prices fall"

"whereby" = by which means — formal cause-and-effect structure

"Deflation is a phenomenon whereby prices fall across the economy."

Advanced & Academic Usage

"the extent to which it applies"

"to which" after "extent" — formal degree expression

"Researchers debated the extent to which genetics influences behaviour."

Advanced & Academic Usage

"which is why she succeeded"

sentential relative — "which" refers to the whole preceding clause

"She practised every day for a year, which is why she succeeded so well."

Advanced & Academic Usage

"a field in which little is known"

fronted preposition + "which" for formal academic statements

"Consciousness remains a field in which very little is definitively known."

Advanced & Academic Usage

"the company, at whose helm he stood"

"at whose helm" — complex possessive with fronted preposition

"He transformed the company, at whose helm he stood for two decades."

Advanced & Academic Usage

"whichever option proves best"

"whichever" = free relative — refers to any option that turns out best

"The committee will adopt whichever option proves most cost-effective."

Frequently Asked Questions

What is the difference between defining and non-defining relative clauses?

A defining relative clause identifies which specific person or thing is meant and cannot be removed without changing the meaning (e.g. "the book that I read"). A non-defining clause adds extra information about something already identified and is always surrounded by commas (e.g. "her first novel, which won the prize"). Removing a non-defining clause leaves the core meaning intact.

Can I use "that" instead of "which" or "who"?

"That" can replace "which" or "who" in defining relative clauses only. It cannot be used in non-defining clauses (after a comma) or directly after a preposition. So "the city in which I was born" is correct formal English, but "the city in that I was born" is wrong. In informal speech, "that" is very common for both people and things in defining clauses.

When should I use "whom" instead of "who"?

"Whom" is used when the relative pronoun functions as the object of the verb or preposition inside the clause — for example "the person whom we hired" or "the director to whom I reported". In formal writing and exams such as IELTS and TOEFL, "whom" is preferred. In everyday speech, most people use "who" in all positions, which is widely accepted.

How do I form a reduced relative clause?

To reduce an active relative clause, remove the relative pronoun and auxiliary verb and use the present participle (-ing): "the man who is waiting" → "the man waiting". For passive clauses, remove the relative pronoun and "be" verb and use the past participle: "the form that was completed" → "the form completed". Reduced clauses are common in formal and academic writing.

What is a sentential relative clause?

A sentential relative clause (also called a "connective relative") uses "which" to refer to a whole preceding clause, not just a noun. For example: "She passed her exam, which surprised her parents." Here "which" refers to the fact that she passed — the entire situation. This structure is common in formal writing and cannot use "that". It is always separated from the main clause by a comma.

The best way to internalise relative clauses is through extensive listening to natural English.

Practise with real English videos →