What is a Non-Defining Relative Clause? ESL Definition with Examples

📚 Quick Study Guide: Non-Defining Relative Clauses

• 📝 Definition: A non-defining relative clause (also known as a non-restrictive relative clause) provides extra, non-essential information about a noun or noun phrase. The sentence would still make sense without it.
• 💡 Key Feature: They are always separated from the rest of the sentence by commas. If you remove the clause, the core meaning of the sentence remains intact.
• 🧐 Pronouns Used: Typically introduced by relative pronouns such as who, whom, whose, which, and where. That is NEVER used in non-defining relative clauses.
• 🔍 Purpose: To add interesting but dispensable details, often about unique people, places, or things.
• ✍️ Punctuation Rule: Always use a comma BEFORE the relative pronoun, and if the clause is in the middle of the sentence, use a comma AFTER the clause as well.
• ❌ "That" Restriction: Remember, "that" cannot be used to introduce a non-defining relative clause. Only "which" for things, and "who/whom" for people.

✅ Practice Quiz: Non-Defining Relative Clauses

1. Which sentence correctly uses a non-defining relative clause?

1. The student who passed the exam celebrated.
2. My brother, who lives in London, visited us last week.
3. The car that is red is mine.
4. I saw the cat which was sleeping on the mat.

2. In the sentence "My dog, who loves to chase squirrels, often barks loudly," what is the non-defining relative clause?

1. My dog
2. who loves to chase squirrels
3. often barks loudly
4. My dog often barks loudly

3. Which relative pronoun CANNOT be used in a non-defining relative clause?

1. who
2. which
3. that
4. whose

4. Choose the sentence where removing the clause in bold would NOT change the main meaning of the sentence significantly.

1. The book that teaches grammar is very popular.
2. Students who study hard usually succeed.
3. My English teacher, who has taught for twenty years, gave us a difficult test.
4. The house where we grew up is being renovated.

5. Add a non-defining relative clause to the sentence: "Paris is a beautiful city."

1. Paris, which is the capital of France, is a beautiful city.
2. Paris that is the capital of France is a beautiful city.
3. Paris who is the capital of France is a beautiful city.
4. Paris where is the capital of France is a beautiful city.

6. Identify the error in the following sentence: "My friend, that lives next door, is a doctor."

1. The comma after 'friend' is incorrect.
2. 'that' should be 'who'.
3. 'next door' should be 'next-door'.
4. 'is a doctor' should be 'is doctor'.

7. Which of the following sentences contains a non-defining relative clause?

1. The car that is parked outside is new.
2. I met a woman who works for Google.
3. Mount Everest, which is the world's highest mountain, is in the Himalayas.
4. People who like to read often visit libraries.