Relative Clauses: Who, Which, That, and Whose
📚 English Grammar Series — Level 3: Advanced (Part 2 of 3)
Relative clauses are how English packs detail into sentences: “The teacher who helped me is very kind.” Instead of two choppy sentences, you get one smooth, elegant one. They’re also where tiny punctuation choices (a comma!) change meaning completely. Let’s go deep.
1. The Relative Pronouns
| Pronoun | For | Example |
|---|---|---|
| who | people (subject/object) | The girl who sits next to me is smart. |
| whom | people (object, formal) | The person whom I met was kind. |
| which | things | The book which I bought was expensive. |
| that | people or things (defining only!) | The movie that we watched was great. |
| whose | possession | The student whose phone rang was embarrassed. |
| where | places | The café where we met is closed. |
| when | times | I’ll never forget the day when we met. |
| why | reasons | Tell me the reason why you’re late. |
2. Defining vs Non-Defining — The Comma That Changes Meaning
Defining — identifies which one. No commas. “That” allowed. The clause is essential:
- The man who/that called you is my uncle. (Which man? The one who called — essential info!)
Non-defining — adds bonus info about something already identified. Commas required. “That” forbidden. You could delete it and the sentence still works:
- My uncle, who lives in Jakarta, is visiting. (I have one uncle — the clause is extra)
- Banjarmasin, which is called the city of a thousand rivers, is beautiful.
⚠️ Watch how commas change meaning:
The students who studied passed. (= only those who studied)
The students, who studied, passed. (= all the students studied, and all passed)
3. Omitting the Pronoun
Object pronoun → can be dropped: The book (which/that) I bought was expensive.
Subject pronoun → must stay: The girl who sits next to me… (can’t drop “who”!)
Quick test: if a verb follows the pronoun directly, it’s the subject — keep it.
4. Prepositions — Formal vs Natural
- Formal (never split, use “whom/which”): The person to whom I spoke was helpful.
- Natural (preposition at the end): The person (who) I spoke to was helpful.
- ⚠️ Never “that” after a preposition: ❌ the house in that I live → ✅ the house in which I live / the house I live in
5. Reduced Relative Clauses — Advanced Compression
Shorten clauses elegantly:
- -ing for active: The girl who is sitting there → The girl sitting there is my sister.
- -ed for passive: The report which was written yesterday → The report written yesterday is excellent.
- Common in signs and news: Passengers wishing to… / A man injured in the accident…
6. Common Mistakes
❌ My brother, that lives in Surabaya, is a doctor. → ✅ My brother, who lives… (no “that” in non-defining!)
❌ The girl which I met… → ✅ The girl who/that I met…
❌ The house where I was born in… → ✅ The house where I was born… (no extra preposition)
❌ The man who I spoke to him… → ✅ The man who I spoke to… (no resumptive pronoun!)
🎯 Tip: take two short sentences from anything you read and fuse them with who/which/that. It’s the fastest path from simple to mature English.
