Welcome to Advanced English Lab! Do you find yourself writing short, choppy sentences like “The man is my uncle. He lives in London”? Combining them into one fluid sentence—“The man who lives in London is my uncle”—is a hallmark of advanced English.
Relative clauses are the essential tools for achieving this fluency. However, the subtle differences between who, whom, which, and that can be confusing. Should you use who or whom? Can you omit the relative pronoun? When do you use which over that?
In this comprehensive guide, we will break down the rules, provide side-by-side comparisons, and reveal the golden rule for omitting relative pronouns. Let us unlock the power of complex sentences!
🎯 What is a Relative Clause?
A relative clause is a group of words that describes or provides more information about a noun. It usually begins with a relative pronoun.
- Purpose: To combine two simple sentences into one complex, elegant sentence.
- Function: To avoid repetition and create smooth, connected speech.
Simple Sentences
“The manager handles our department.” + “He is on vacation.”
Combined with Relative Clause
“The manager who handles our department is on vacation.”
📘 The Relatives: Who, Whom, Which & That
Here is your quick-reference guide to the main relative pronouns:
| Pronoun | Used For | Role in Clause | Example |
|---|---|---|---|
| Who | People 👤 | Subject (Doer) | The woman who called you is here. |
| Whom | People 👤 | Object (Receiver) | The woman whom you called is here. |
| Which | Things & Animals 🐶 | Subject or Object | The car which hit the tree was red. |
| That | People, Things, & Animals 🧑🤝🧑 | Subject or Object | The car that hit the tree was red. |
1. Who – The Subject for People
Who refers to people and functions as the subject of the relative clause. It performs the action.
- “The athlete who broke the world record…” (Who broke the record? The athlete.)
- “The artist who painted this masterpiece…” (Who painted it? The artist.)
2. Whom – The Object for People (Formal)
Whom refers to people and functions as the object of the relative clause. It receives the action. In everyday conversation, whom is often replaced by who or omitted entirely, but it remains important in formal writing.
- “The actor whom we saw at the restaurant…” (We saw whom? The actor.)
- “The guest whom they invited…” (They invited whom? The guest.)
3. Which – For Things & Animals
Which refers to animals and things (never people). It can serve as either the subject or the object of the clause.
- Subject: “The window which faces the garden…” (Which faces? The window.)
- Object: “The outfit which she wore…” (She wore which? The outfit.)
4. That – The Versatile All-Rounder
That is the most flexible pronoun. It can refer to people, animals, and things. It can act as both subject and object. In many cases, it can replace who and which in restrictive clauses.
- “The company that specializes in tech gadgets…” (Subject, Thing)
- “The snack that she brought…” (Object, Thing)
- “John met a girl that works at a bank…” (Subject, Person)
🔥 The Golden Rules of Omission
This is the most critical part of mastering relative clauses: Can you leave the relative pronoun out?
The answer depends entirely on the pronoun’s role in the clause.
Rule 1: Subject – NEVER Omit ❌
If the relative pronoun is the subject of the relative clause (i.e., it is directly followed by a verb), you cannot omit it.
- The manager who handles our department is on vacation.
- (Who handles? Who is the subject of handles. ❌ Cannot remove who.)
- A company that specializes in tech gadgets…
- (That specializes? That is the subject of specializes. ❌ Cannot remove that.)
- The dogs that are rescued…
- (That are rescued? That is the subject of are rescued. ❌ Cannot remove that.)
💡 Memory Trick: If you see a verb directly after the pronoun, KEEP the pronoun.
Rule 2: Object – You CAN Omit ✅
If the relative pronoun is the object of the relative clause (i.e., it is followed by a subject + verb), you can omit it.
- The outfit (that/which) she wore…
- (She wore what? The pronoun is the object of wore. ✅ You can omit it.)
- Result: “The outfit she wore…”
- The movie (that) I saw yesterday…
- (I saw what? The pronoun is the object of saw. ✅ You can omit it.)
- Result: “The movie I saw yesterday…”
- The actor (whom/that) we saw…
- (We saw whom? The pronoun is the object of saw. ✅ You can omit it.)
- Result: “The actor we saw…”
💡 Memory Trick: If you see a noun/pronoun (subject) after the relative pronoun, you can likely REMOVE the relative pronoun.
📊 Subject vs. Object: The Visual Decision Tree
| Structure | Example | Can you omit the pronoun? |
|---|---|---|
| Pronoun + Verb | …who works hard. | ❌ No (Subject) |
| Pronoun + Subject + Verb | …(that) we met. | ✅ Yes (Object) |
✍️ Compare Side-by-Side
| Role | Pronoun Kept (Correct) | Pronoun Omitted (Correct) |
|---|---|---|
| Subject | The artist who painted this… | ❌ The artist painted this… (Now it reads like a main clause) |
| Object | The artist (whom) we saw… | ✅ The artist we saw… |
🧩 Quiz Review: Applying the Rules
Let us apply these rules to the quiz examples from the lesson.
| Question | Relative Clause | Subject or Object? | Can it be omitted? | Why? |
|---|---|---|---|---|
| “A company that specializes in tech gadgets…” | that specializes | Subject (That specializes) | ❌ No | The pronoun is followed directly by a verb. |
| “The athlete who broke the world record…” | who broke | Subject (Who broke) | ❌ No | The pronoun is followed directly by a verb. |
| “The outfit (that/which) she wore…” | (that/which) she wore | Object (She wore it) | ✅ Yes | The pronoun is followed by a subject (she) and verb (wore). |
| “The dogs that are rescued…” | that are rescued | Subject (That are rescued) | ❌ No | Pronoun + Verb. |
| “The actor (whom/that) we saw…” | (whom/that) we saw | Object (We saw him) | ✅ Yes | Pronoun + Subject (we) + Verb (saw). |
| “The window that faces the garden…” | that faces | Subject (That faces) | ❌ No | Pronoun + Verb. |
| “The artist who painted…” | who painted | Subject (Who painted) | ❌ No | Pronoun + Verb. |
| “The book (that/which) she lost…” | (that/which) she lost | Object (She lost it) | ✅ Yes | Pronoun + Subject + Verb. |
| “John met a girl who works…” | who works | Subject (Who works) | ❌ No | Pronoun + Verb. |
| “The snack (that/which) she brought…” | (that/which) she brought | Object (She brought it) | ✅ Yes | Pronoun + Subject + Verb. |
❌ Common Mistakes to Avoid
| ❌ Incorrect | ✅ Correct | Reason |
|---|---|---|
| The man works in my office is friendly. | The man who works in my office is friendly. | Subject pronoun who is required. |
| The movie which I saw it was good. | The movie (which) I saw was good. | Remove the extra object it. The pronoun which already acts as the object. |
| The person which called you… | The person who called you… | Which is for things; use who for people. |
| The car who hit the tree… | The car which/that hit the tree… | Who is for people; use which/that for things. |
| She is the woman whom won the race. | She is the woman who won the race. | Whom is an object; who is the subject of won. |
📝 Final Summary
Mastering relative clauses will transform your writing and speaking from basic to sophisticated.
Your golden checklist:
- Who 👤 + Subject (Person)
- Whom 👤 + Object (Person, Formal)
- Which 🐶 + Subject/Object (Thing/Animal)
- That 🧑🤝🧑 + Subject/Object (Person/Thing/Animal)
- Omit? ❌ Keep if followed by a verb (Subject). ✅ Omit if followed by a subject (Object).
📚 Ready to perfect your English grammar? Visit www.advancedenglishlab.com for expert lessons, interactive exercises, and advanced learning resources!
Leave a Reply