1️⃣ What Is a Relative Clause?
Mastering relative clauses in English is an important skill. A relative clause (also called an adjective clause) is a dependent clause that describes or gives more information about a noun.
It usually begins with a relative pronoun such as:
- who
- which
- that
- whose
- where
A relative clause answers the question:
Which one? What kind? Whose?
Example:
The student who won the scholarship studied every day.
- Main noun: student
- Relative clause: who won the scholarship
- Function: identifies which student
The clause cannot stand alone. It depends on the noun it modifies.
Relative clauses are a type of dependent clause. If you want to strengthen your understanding of how clauses work in English, review this guide first:
Independent and Dependent Clauses in English: How to Write Clear Sentences
2️⃣ Restrictive vs. Nonrestrictive Clauses
| Feature | Restrictive Clause | Nonrestrictive Clause |
|---|---|---|
| Purpose | Identifies which noun | Adds extra information |
| Meaning | Essential | Additional |
| Commas | No commas | Commas required |
| Information Hierarchy | High importance | Secondary importance |
| Pronoun Use | that / who / which | who / which (not that) |
🔹 Restrictive = Necessary Information
Without the clause, the meaning changes or becomes unclear.
Example:
The employees who work remotely need secure access.
- Main noun: employees
- Relative clause: who work remotely
- Function: identifies which employees – only remote employees
🔹 Nonrestrictive = Extra Information
The noun is already clear. The clause just adds detail.
Example:
The employees, who work remotely, need secure access.
- Main noun: employees
- Relative clause: who work remotely
- Function: identifies which employees – all employees
Information Hierarchy
Think of it as:
Restrictive → limits or defines the noun
Nonrestrictive → adds optional, non-essential (extra) information
How Meaning Changes
Pair 1: People
A. The teachers who arrived late apologized.
→ Only the late teachers apologized.B. The teachers, who arrived late, apologized.
→ All the teachers arrived late.
Pair 2: Objects
A. The books that are on the table are mine.
→ Only the books on the table.B. The books, which are on the table, are mine.
→ All the books are on the table.
3️⃣ Relative Pronouns (who, which, that, whose, where)
Relative pronouns introduce a relative clause and connect it to the noun it describes.
They do two jobs:
- They refer back to the noun (the antecedent).
- They act as part of the clause (subject, object, or possessive).
| Pronoun | Refers to | Subject example | Object example | Notes |
|---|---|---|---|---|
| who | People | The manager who leads the team is experienced. | The candidate (who) we interviewed was confident. | Object who is often omitted in speech. Whom is formal. |
| which | Things | The report which explains the results is attached. | The report (which) I reviewed was detailed. | After commas, use which (not that). |
| that | People / Things | The student that won the prize is here. | The book (that) I bought is excellent. | Restrictive only. Never after a comma. |
| whose | People / Things | The women whose husbands are wealthy went on a shopping spree. | Shows possession/relationship. Can refer to things in formal English. | |
| where | Places | The restaurant where we met has closed. | More formal: in which we met. | |
Quick Selection Rule
- Person → who
- Thing → which
- Restrictive (informal) → that
- Possession → whose
- Place → where
Understanding subject and object roles is essential for using relative clauses correctly — especially when deciding if you can omit the relative pronoun.
Review here:
Mastering Direct and Indirect Objects in English
4️⃣ Omitting the Relative Pronoun
You can omit the relative pronoun only when it functions as the object of the relative clause. If the pronoun is the subject of the clause, you cannot omit it.
When You CAN Omit It (Object)
Full: The book that I bought is excellent.
Omitted: The book I bought is excellent.
In the clause (that) I bought, the subject is I. The relative pronoun is the object of bought, so it can be removed.
Full: The person who we met was helpful.
Omitted: The person we met was helpful.
When You CANNOT Omit It (Subject)
Full: The student who won the prize is here.
Incorrect: ❌ The student won the prize is here.
In who won the prize, who is the subject of won. If you remove it, the clause has no subject.
Quick Test
- If the clause already has a subject (e.g., I / we / they), you can often omit the pronoun: the book (that) I bought.
- If the relative pronoun is followed directly by a verb, do not omit it: the student who won.
5️⃣ Advanced Forms: Reduced Relative Clauses
A reduced relative clause is a shortened form of a relative clause.
We can reduce a relative clause when:
- The relative pronoun is the subject of the clause.
- The verb allows structural simplification.
- The meaning remains clear after reduction.
Reduced clauses are common in formal, academic, and professional writing because they make sentences more concise.
✅ When Reduction Is Possible
There are two advanced forms:
1️⃣ Passive Form → Past Participle
If the relative clause contains be + past participle, remove:
- the relative pronoun
- the form of be
Structure:
Full:
Noun + that/which + be + past participle
Reduced:
Noun + past participle
Full:
The documents that were submitted yesterday are missing.Reduced:
The documents submitted yesterday are missing.
Full:
The products which are manufactured in Germany are expensive.Reduced:
The products manufactured in Germany are expensive.
Full:
The proposal that was approved by the board will be implemented.Reduced:
The proposal approved by the board will be implemented.
2️⃣ Active Form with -ing (Present Participle)
If the relative clause contains who/that + be + verb-ing, remove the relative pronoun and be.
Structure:
Full:
Noun + who/that + be + verb-ing
Reduced:
Noun + verb-ing
Full:
The students who are preparing for the exam look stressed.Reduced:
The students preparing for the exam look stressed.
Full:
The company that is expanding rapidly needs more staff.Reduced:
The company expanding rapidly needs more staff.
Full:
The man who was standing near the door left early.Reduced:
The man standing near the door left early.
❌ When Reduction Is NOT Possible
There are two advanced cases where reduction is not possible:
1️⃣ Active Finite Clause Without “Be”
If the clause contains a normal active verb (no form of be), do not reduce it.
Full:
The employee who works in accounting received a promotion.Incorrect:
❌ The employee works in accounting received a promotion.
The verb works is a finite verb, and who is the subject. Removing it creates a grammatical error.
2️⃣ When Meaning Becomes Ambiguous
Some reductions are grammatically possible but may change emphasis or clarity.
Full:
The professor who lives next door is retiring.Reduced:
The professor living next door is retiring.
This is grammatically correct, but depending on context, it may suggest temporary description rather than clear identification.
⚠️ Common Mistakes with Relative Clauses
1️⃣ Missing commas in nonrestrictive clauses
❌ My brother who lives in Dallas is visiting.
✅ My brother, who lives in Dallas, is visiting.
(Use commas when the information is extra, not essential.)
2️⃣ Using “that” after a comma
❌ The report, that explains the results, is attached.
✅ The report, which explains the results, is attached.
(“That” is only used in restrictive clauses.)
3️⃣ Omitting the relative pronoun incorrectly
❌ The student won the prize is here.
✅ The student who won the prize is here.
(Do not omit the pronoun when it is the subject of the clause.)
4️⃣ Confusing “who’s” and “whose”
❌ The company who’s products are popular is expanding.
✅ The company whose products are popular is expanding.
(Who’s = who is. Whose = possession.)
5️⃣ Reducing clauses incorrectly
❌ The employee works in marketing received a bonus.
✅ The employee who works in marketing received a bonus.
(Only reduce when the structure allows it.)
🌎 Spanish Speaker Notes
If Spanish is your first language, pay attention to these differences:
1️⃣ “Que” vs. “Who”
Spanish uses que for people and things.
In English, use who for people.
❌ The student that won the prize…
✅ The student who won the prize…
2️⃣ Commas Change Meaning
English is strict about restrictive vs. nonrestrictive clauses.
Commas are not optional — they change the meaning of the sentence.
3️⃣ Don’t Avoid “Whose”
Spanish often uses que + su instead of cuyo.
In English, whose is natural — even for things.
✅ The company whose products are popular…
4️⃣ Omission Works Differently
In English, you can sometimes omit the relative pronoun:
✅ The book (that) I bought
This does not work the same way in Spanish.
Let’s Practice Relative Clauses
Exercise A
Complete the paragraph using a relative pronoun from the word bank.
You may use some pronouns more than once.
Word Bank
who which that whose where
Paragraph
Last year, I joined a company (1) ______ develops renewable energy solutions. The CEO, (2) ______ founded the organization in 2008, believes strongly in innovation. The company works with engineers (3) ______ specialize in sustainable design and researchers (4) ______ ideas are changing the industry.
We recently completed a project (5) ______ was funded by a European agency. The building (6) ______ we constructed uses solar panels and recycled materials. The architect (7) ______ we hired had previously designed offices (8) ______ focus on energy efficiency.
One of the challenges (9) ______ we faced involved reducing costs without lowering quality. The strategy (10) ______ we implemented proved successful.
Exercise B
Part 1 – Omit the Relative Pronoun (If Possible)
- The movie that we watched was fascinating.
- The woman who called earlier left a message.
- The article that I read was controversial.
- The student who won the prize is here.
- The candidate who we interviewed was confident.
Part 2 – Reduce the Relative Clause (If Possible)
- The documents that were signed yesterday are missing.
- The students who are studying abroad often face challenges.
- The employee who works in marketing received a bonus.
- The products which are produced locally are cheaper.
- The man who was sitting near the window left early.
Scoring & Feedback
🔵 17 – 20 Correct
Excellent work! 🎉 You really understand how to use adjective clauses. Keep using it in your everyday conversations and writing.
🟢14 – 16 Correct
Great job! ✅ You have a good understanding of adjective clauses. Review the ones you missed.
🟡12 – 13 Correct
Good effort! 💪You’re learning, and that’s what matters. Take a moment to review the examples and do the quiz again.
🔴 0 – 11 Correct
No worries! 🌱 Adjective clauses can be tricky at first. Go back and review the examples in the lesson.
Relative clauses are a powerful tool for writing clearer, more sophisticated sentences. By understanding how restrictive and nonrestrictive clauses work, when pronouns can be omitted, and how advanced reductions function, you move from intermediate grammar to confident B2-level communication. If you’d like guided practice using these structures in real conversation and writing tasks, explore our English lessons for personalized support.
Remember! Learning a language is not about perfection—it’s about progress. Keep practicing, stay curious, and trust the process. You are moving beyond English to more opportunities, connections, and self-expression!
