Introduction
A relative clause error correction quiz is an effective way to improve English grammar, sentence structure, and writing accuracy. Whether you are preparing for a school examination, improving your business English, or learning English as a second language, understanding relative clauses can help you communicate more clearly.
Relative clauses allow us to add information about people, places, objects, and situations without writing several separate sentences.
For example:
- Incorrect: The woman which teaches English is very friendly.
- Correct: The woman who teaches English is very friendly.
The mistake looks small, but it can make a sentence grammatically incorrect.
In this guide, you will learn the rules of relative clauses, identify common mistakes, and practise 100 original error correction questions with answers. The examples cover everyday conversations, academic writing, professional communication, and advanced grammar.
Think of relative clauses as helpful assistants. They add useful information, but sometimes they bring the wrong pronoun to work!
What Is a Relative Clause?
A relative clause is a dependent clause that describes or identifies a noun or noun phrase. It usually begins with a relative pronoun such as who, whom, whose, which, or that, or a relative adverb such as where, when, or why.
Example:
The student who won the scholarship thanked her teachers.
Here, who won the scholarship is the relative clause. It provides additional information about the student.
Relative Pronouns and Their Uses
| Relative Word | Main Use | Example |
|---|---|---|
| Who | Refers to people | The doctor who treated me was kind. |
| Whom | Refers to people as objects, especially in formal English | The professor whom we invited arrived early. |
| Whose | Expresses possession | The author whose book won the award is speaking. |
| Which | Refers to things or animals | The laptop which I purchased works well. |
| That | Refers to people or things in defining clauses | The movie that we watched was interesting. |
| Where | Refers to places | This is the town where I grew up. |
| When | Refers to times | I remember the day when we first met. |
| Why | Refers to reasons | That is the reason why she resigned. |
Important: In many defining relative clauses, who, which, and that can overlap in usage. However, that is not normally used to introduce a non-defining relative clause.
Types of Relative Clauses
1. Defining Relative Clauses
A defining relative clause gives essential information that identifies the person or thing being discussed.
Example: The employee who manages the accounts is on leave.
Without the relative clause, we may not know which employee is being discussed.
Rule: Do not separate a defining relative clause with commas.
2. Non-Defining Relative Clauses
A non-defining relative clause adds extra information about someone or something already identified.
Example: My brother, who lives in Canada, is visiting us.
The information about Canada is additional, not essential for identifying the brother.
Rule: Use commas around a non-defining relative clause when it appears in the middle of a sentence. Do not use that as its relative pronoun.
3. Reduced Relative Clauses
A reduced relative clause is a shorter form of certain relative clauses.
Full clause: The students who are waiting outside are from Australia.
Reduced clause: The students waiting outside are from Australia.
Not every relative clause can be reduced, so always check whether the meaning remains clear.
Relative Clause Error Correction Quiz: Essential Grammar Rules
Follow these steps to identify and correct relative clause mistakes.
Step 1: Identify the noun being described.
In The woman who called is my teacher, the relative clause describes the woman.
Step 2: Choose the correct relative word.
Use who for a person acting as the subject, whose for possession, and which for things. That is also possible in many defining clauses.
Step 3: Check the relative clause’s subject and verb.
Incorrect: The boy who play cricket is my cousin.
Correct: The boy who plays cricket is my cousin.
Step 4: Check whether the clause needs commas.
Incorrect: My father, who works in a hospital is retiring.
Correct: My father, who works in a hospital, is retiring.
Step 5: Remove unnecessary repeated pronouns.
Incorrect: The book that I bought it is expensive.
Correct: The book that I bought is expensive.
Step 6: Check whether the relative pronoun can be omitted.
Correct: The movie that we watched was excellent.
Also correct: The movie we watched was excellent.
However, in The woman who called me, you cannot omit who because it is the subject of the relative clause.
100 Relative Clause Error Correction Questions With Answers
The following exercises move from basic grammar to advanced sentence correction. Each question contains an error or an awkward construction that needs improvement.
Some answers have more than one acceptable form. The answer key gives a natural, grammatically correct version, with explanations where needed.
Part 1: Basic Relative Clause Questions (1–20)
| No. | Incorrect Sentence | Correct Sentence |
|---|---|---|
| 1 | The girl which sings beautifully is my sister. | The girl who sings beautifully is my sister. |
| 2 | The man whose lives next door is a doctor. | The man who lives next door is a doctor. |
| 3 | This is the phone who I purchased yesterday. | This is the phone that I purchased yesterday. |
| 4 | The teacher which helped us is very patient. | The teacher who helped us is very patient. |
| 5 | The boy who bicycle was stolen is upset. | The boy whose bicycle was stolen is upset. |
| 6 | I met a woman which speaks five languages. | I met a woman who speaks five languages. |
| 7 | The restaurant who serves Italian food is nearby. | The restaurant that serves Italian food is nearby. |
| 8 | The student whose won the prize is absent. | The student who won the prize is absent. |
| 9 | The car who broke down belongs to my uncle. | The car that broke down belongs to my uncle. |
| 10 | The doctor which examined me was helpful. | The doctor who examined me was helpful. |
| 11 | The woman who daughter studies abroad is my neighbour. | The woman whose daughter studies abroad is my neighbour. |
| 12 | This is the bag who I lost last week. | This is the bag that I lost last week. |
| 13 | The actor which appeared on television is famous. | The actor who appeared on television is famous. |
| 14 | The dog who tail is injured needs treatment. | The dog whose tail is injured needs treatment. |
| 15 | The people which attended the meeting were satisfied. | The people who attended the meeting were satisfied. |
| 16 | The computer who stopped working is new. | The computer that stopped working is new. |
| 17 | The girl whom won the race is my friend. | The girl who won the race is my friend. |
| 18 | The house who roof was damaged needs repairs. | The house whose roof was damaged needs repairs. |
| 19 | The journalist which interviewed the minister asked important questions. | The journalist who interviewed the minister asked important questions. |
| 20 | The song who became popular was written last year. | The song that became popular was written last year. |
Explanation: Questions 1–20 mainly test the difference between who, whose, which, and that. Remember that whose expresses possession and who normally identifies a person performing an action.
Part 2: Intermediate Relative Clause Questions (21–40)
| No. | Incorrect Sentence | Correct Sentence |
|---|---|---|
| 21 | The woman who I spoke to her was helpful. | The woman who I spoke to was helpful. |
| 22 | The book that I borrowed it was fascinating. | The book that I borrowed was fascinating. |
| 23 | The person whom called yesterday left a message. | The person who called yesterday left a message. |
| 24 | The hotel which we stayed was comfortable. | The hotel where we stayed was comfortable. |
| 25 | The year where I graduated was unforgettable. | The year when I graduated was unforgettable. |
| 26 | The reason where he resigned remains unclear. | The reason why he resigned remains unclear. |
| 27 | The student who studies hard usually achieve good results. | The student who studies hard usually achieves good results. |
| 28 | The employees who works remotely attend weekly meetings. | The employees who work remotely attend weekly meetings. |
| 29 | The laptop that I bought it last month is already faulty. | The laptop that I bought last month is already faulty. |
| 30 | The woman whose I met yesterday is a scientist. | The woman whom I met yesterday is a scientist. |
| 31 | The office where I work in is on the third floor. | The office where I work is on the third floor. |
| 32 | The city where I visited last summer was beautiful. | The city that I visited last summer was beautiful. |
| 33 | The teacher who students respect him is retiring. | The teacher who students respect is retiring. |
| 34 | The company which headquarters are in London is expanding. | The company whose headquarters are in London is expanding. |
| 35 | The day which we first met was memorable. | The day when we first met was memorable. |
| 36 | The article who you recommended was informative. | The article that you recommended was informative. |
| 37 | The friend whose helped me deserves thanks. | The friend who helped me deserves thanks. |
| 38 | The reason why she left because she was tired. | The reason she left was that she was tired. |
| 39 | The project which we are working is important. | The project which we are working on is important. |
| 40 | The candidate who the manager selected him accepted the offer. | The candidate who the manager selected accepted the offer. |
Explanation: These questions test repeated object pronouns, relative adverbs, missing prepositions, and subject-verb agreement.
For example, the hotel where we stayed is correct because where already expresses the location. Adding in after stayed is unnecessary in that construction.
Part 3: Advanced Relative Clause Questions (41–60)
| No. | Incorrect Sentence | Correct Sentence |
|---|---|---|
| 41 | My uncle, that lives in Ireland, is visiting us. | My uncle, who lives in Ireland, is visiting us. |
| 42 | The proposal, that was submitted yesterday, needs revision. | The proposal, which was submitted yesterday, needs revision. |
| 43 | The scientist, who research changed medicine, received an award. | The scientist, whose research changed medicine, received an award. |
| 44 | The conference which I attended it was useful. | The conference which I attended was useful. |
| 45 | The professor to who I sent the report replied quickly. | The professor to whom I sent the report replied quickly. |
| 46 | The company for who she works is expanding. | The company for which she works is expanding. |
| 47 | The method by that the results were obtained is reliable. | The method by which the results were obtained is reliable. |
| 48 | The manager, whom approved the plan, resigned. | The manager, who approved the plan, resigned. |
| 49 | The research, that took three years, produced valuable findings. | The research, which took three years, produced valuable findings. |
| 50 | The building in where the meeting took place is historic. | The building where the meeting took place is historic. |
| 51 | The applicant, whose qualifications were impressive, she received an offer. | The applicant, whose qualifications were impressive, received an offer. |
| 52 | The document to that I referred is confidential. | The document to which I referred is confidential. |
| 53 | The village, that is surrounded by mountains, attracts tourists. | The village, which is surrounded by mountains, attracts tourists. |
| 54 | The author whose novel was shortlisted, received international attention. | The author whose novel was shortlisted received international attention. |
| 55 | The equipment which was purchased last year it requires maintenance. | The equipment which was purchased last year requires maintenance. |
| 56 | The committee, who members disagreed, postponed the vote. | The committee, whose members disagreed, postponed the vote. |
| 57 | The decision for which we are waiting for is important. | The decision for which we are waiting is important. |
| 58 | The engineer, which designed the bridge, received recognition. | The engineer, who designed the bridge, received recognition. |
| 59 | The system which was installed yesterday, is working correctly. | The system which was installed yesterday is working correctly. |
| 60 | The employee, whom report was praised, received a promotion. | The employee, whose report was praised, received a promotion. |
Explanation: Advanced relative clause questions often involve punctuation, formal preposition placement, and non-defining clauses.
Remember that a preposition placed before a relative pronoun normally requires whom for people or which for things, not who or that.
Part 4: Daily Conversation Examples (61–70)
| No. | Incorrect Sentence | Correct Sentence |
|---|---|---|
| 61 | That’s the neighbour which helped us move. | That’s the neighbour who helped us move. |
| 62 | I lost the umbrella who you gave me. | I lost the umbrella that you gave me. |
| 63 | The cafe where we met at has closed. | The cafe where we met has closed. |
| 64 | The friend whose called me sounded excited. | The friend who called me sounded excited. |
| 65 | The shoes who I ordered arrived today. | The shoes that I ordered arrived today. |
| 66 | That’s the park which we usually play. | That’s the park where we usually play. |
| 67 | The neighbour who dog barks loudly is away. | The neighbour whose dog barks loudly is away. |
| 68 | I found the keys which I had lost them. | I found the keys which I had lost. |
| 69 | The person whom lives upstairs is a musician. | The person who lives upstairs is a musician. |
| 70 | This is the shop where I bought my jacket from. | This is the shop where I bought my jacket. |
Explanation: In everyday speech, relative pronouns are sometimes omitted when they function as objects.
For example, I lost the umbrella you gave me is also correct.
Part 5: Academic Writing Examples (71–80)
| No. | Incorrect Sentence | Correct Sentence |
|---|---|---|
| 71 | The researchers which conducted the study published their findings. | The researchers who conducted the study published their findings. |
| 72 | The theory, that was introduced in 1990, remains influential. | The theory, which was introduced in 1990, remains influential. |
| 73 | The participants whose completed the survey received certificates. | The participants who completed the survey received certificates. |
| 74 | The data which was collected it revealed a pattern. | The data which was collected revealed a pattern. |
| 75 | The laboratory where the experiment was conducted in is well equipped. | The laboratory where the experiment was conducted is well equipped. |
| 76 | The professor whom supervised the research has retired. | The professor who supervised the research has retired. |
| 77 | The study, which findings were widely discussed, influenced policy. | The study, whose findings were widely discussed, influenced policy. |
| 78 | The evidence that supports the conclusion, was reviewed carefully. | The evidence that supports the conclusion was reviewed carefully. |
| 79 | The institution for who the research was conducted funded the project. | The institution for which the research was conducted funded the project. |
| 80 | The period where the population increased rapidly was examined. | The period when the population increased rapidly was examined. |
Explanation: Academic writing requires precise connections between ideas. Formal structures such as for which and whose findings are particularly useful in research reports and essays.
Part 6: Business and Professional Examples (81–90)
| No. | Incorrect Sentence | Correct Sentence |
|---|---|---|
| 81 | The manager which approved the budget is unavailable. | The manager who approved the budget is unavailable. |
| 82 | The client whose requested the update is waiting. | The client who requested the update is waiting. |
| 83 | The report that we submitted it needs correction. | The report that we submitted needs correction. |
| 84 | The company, that opened a new office, hired 50 employees. | The company, which opened a new office, hired 50 employees. |
| 85 | The consultant to who we spoke suggested improvements. | The consultant to whom we spoke suggested improvements. |
| 86 | The department whose handles recruitment is expanding. | The department that handles recruitment is expanding. |
| 87 | The employees who attends training improve their skills. | The employees who attend training improve their skills. |
| 88 | The software which our team depends is temporarily unavailable. | The software which our team depends on is temporarily unavailable. |
| 89 | The supplier who products were delayed apologised. | The supplier whose products were delayed apologised. |
| 90 | The policy, which was updated last week is now effective. | The policy, which was updated last week, is now effective. |
Explanation: In professional communication, relative clauses help specify people, documents, responsibilities, and processes without repeating unnecessary information.
Part 7: Email Writing Examples (91–100)
| No. | Incorrect Sentence | Correct Sentence |
|---|---|---|
| 91 | Please contact the officer which manages your account. | Please contact the officer who manages your account. |
| 92 | I have attached the file which you requested it. | I have attached the file which you requested. |
| 93 | The colleague whose sent the invitation will assist you. | The colleague who sent the invitation will assist you. |
| 94 | The meeting, that was scheduled for Friday, has been postponed. | The meeting, which was scheduled for Friday, has been postponed. |
| 95 | The customer to who you replied has responded. | The customer to whom you replied has responded. |
| 96 | The form which you need to complete it is attached. | The form which you need to complete is attached. |
| 97 | The representative who contact details appear below will help you. | The representative whose contact details appear below will help you. |
| 98 | The deadline when we discussed yesterday remains unchanged. | The deadline that we discussed yesterday remains unchanged. |
| 99 | The instructions which were shared yesterday, are still valid. | The instructions which were shared yesterday are still valid. |
| 100 | The applicant whom has submitted the documents will receive confirmation. | The applicant who has submitted the documents will receive confirmation. |
Explanation: In business emails, relative clauses can make messages shorter and clearer. They are particularly helpful when referring to attachments, previous conversations, customers, deadlines, and colleagues.
Common Relative Clause Mistakes and How to Avoid Them
| Common Mistake | Incorrect | Correct | Grammar Rule |
|---|---|---|---|
| Wrong pronoun for people | The nurse which called | The nurse who called | Use who for people |
| Wrong possessive pronoun | The child who bag is missing | The child whose bag is missing | Use whose for possession |
| Repeated object | The file that I opened it | The file that I opened | Avoid unnecessary repeated pronouns |
| Wrong subject agreement | The workers who arrives | The workers who arrive | Match the verb to its subject |
| Incorrect comma | The book, that I need is missing | The book that I need is missing | No commas in defining clauses |
| That in a non-defining clause | My aunt, that lives abroad | My aunt, who lives abroad | Use who or which, not that |
| Missing preposition | The issue which we talked | The issue which we talked about | Keep required prepositions |
| Incorrect relative adverb | The day where we met | The day when we met | Use when for time |
| Incorrect whom | The person whom called | The person who called | Use who as a subject |
| Unnecessary comma | The employees who arrived early, received awards | The employees who arrived early received awards | Do not separate a subject from its main verb |
Easy Tips to Remember Relative Clause Rules
- Who = person: The student who answered correctly.
- Whose = possession: The student whose notebook is missing.
- Which = thing: The camera which stopped working.
- That = defining information: The documents that we need.
- Where = place: The school where I studied.
- When = time: The year when she graduated.
- Why = reason: The reason why they left.
- Whom = object: The applicant whom we interviewed.
A useful memory trick is to ask three questions: Who or what am I describing? Is the information essential? Does the clause already have a subject or object?
These checks can prevent many common errors.
Practice Exercises: Test Your Relative Clause Knowledge
Now that you have reviewed 100 corrected examples, try these additional exercises without looking at the answers.
Exercise A: Correct the Sentences
- The woman which teaches French is my neighbour.
- The article who appeared online was informative.
- The employee whose submitted the report is absent.
- The university where I studied at is well known.
- The applicant whom passed the interview received an offer.
- The film, that won several awards, is worth watching.
- The engineer who designs the machines have resigned.
- The documents that you requested them are attached.
- The reason where she changed her decision is unclear.
- The researcher to who we sent the results has replied.
Exercise A: Answer Key
| No. | Correct Answer | Explanation |
|---|---|---|
| 1 | The woman who teaches French is my neighbour. | Who refers to a person. |
| 2 | The article that appeared online was informative. | That can refer to a thing in a defining clause. |
| 3 | The employee who submitted the report is absent. | Who functions as the subject. |
| 4 | The university where I studied is well known. | Remove the unnecessary at. |
| 5 | The applicant who passed the interview received an offer. | Use who as the subject. |
| 6 | The film, which won several awards, is worth watching. | Use which in a non-defining clause. |
| 7 | The engineer who designs the machines has resigned. | The main subject engineer is singular. |
| 8 | The documents that you requested are attached. | Remove the repeated object pronoun. |
| 9 | The reason why she changed her decision is unclear. | Why introduces the reason. |
| 10 | The researcher to whom we sent the results has replied. | Use whom after the preposition to. |
Frequently Asked Questions About Relative Clauses
1. What is a relative clause in English grammar?
A relative clause is a dependent clause that describes or identifies a noun or noun phrase. It usually begins with a relative pronoun such as who, whose, which, or that. For example, in The student who won the award is my friend, the words who won the award form the relative clause.
2. What is the difference between who, whom, and whose?
Who normally functions as a subject, whom functions as an object, and whose indicates possession.
For example:
- The teacher who called is helpful.
- The teacher whom we invited is helpful.
- The teacher whose class won is helpful.
In everyday English, who often replaces whom when it functions as an object.
3. What is the difference between defining and non-defining relative clauses?
A defining relative clause provides essential identifying information and does not require commas. A non-defining relative clause adds supplementary information and is separated by commas.
For example:
- Defining: The employees who completed training received certificates.
- Non-defining: Our manager, who completed training last week, received a certificate.
4. Can we omit relative pronouns in English?
Yes, a relative pronoun can often be omitted when it functions as the object of a defining relative clause.
For example, The book that I bought is interesting can become The book I bought is interesting.
However, a subject relative pronoun cannot normally be omitted from a full relative clause. Non-defining relative pronouns also cannot be omitted.
5. How can I improve my relative clause error correction skills?
Start by learning the functions of relative pronouns. Then practise identifying defining and non-defining clauses, checking subject-verb agreement, removing unnecessary repeated pronouns, and correcting punctuation.
Regular practice with error correction exercises, particularly those that explain the answers, can help develop greater grammatical accuracy.
Conclusion
Mastering relative clauses is an important step towards writing accurate, natural, and professional English.
This relative clause error correction quiz provides 100 examples covering basic, intermediate, and advanced grammar. It also includes everyday conversation, academic writing, business communication, and email examples.
The most important rules to remember are simple: choose the correct relative word, use commas appropriately, check verb agreement, and avoid repeating unnecessary pronouns.
Relative clauses may be small, but they have a big responsibility. One misplaced pronoun can turn a perfectly good sentence into a grammar puzzle!
Keep practising, review your mistakes, and apply these rules whenever you write or speak English.
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Disclaimer
This article is intended for educational purposes and general English grammar practice. Some relative clause constructions have more than one grammatically acceptable answer, depending on context, formality, and regional English usage. Both US and UK English conventions have been considered. Learners should follow the specific grammar guidelines provided by their school, examination board, or institution when preparing for formal assessments.
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