The Grammar Lab: Defining vs. Non-Defining Clauses

The Grammar Lab: Relative Clauses

Lesson 11: Defining vs. Non-Defining

Essential or Extra?

Some clauses identify exactly who we are talking about (Defining). Others just give extra information (Non-Defining). The secret is in the comma.

🔹 Defining: No commas. Necessary info. (ឃ្លាបញ្ជាក់ន័យ)
🔹 Non-Defining: Has commas. Extra info. (ឃ្លាពន្យល់បន្ថែម)

Defining ID Card 🪪

Tells us which one. Without it, we don't know who/what. NO COMMAS.

The man who called is my dad.	(Which man?)
The car that I bought is red.	(Which car?)

Non-Defining Accessory 🧣

Adds extra detail. We already know who/what. USE COMMAS.

My dad, who called, is here.	(We know it's dad)
Paris, which is big, is nice.	(Everyone knows Paris)

The "That" Trap ⚠️ Warning

Never use "That" after a comma.
In Non-Defining clauses, you must use Who (people) or Which (things).

My car, which is old...	Correct ✅
My car, that is old...	Wrong ❌

Comma Power

Click to see how the meaning changes.

My brother who lives in USA...Defining (I have many brothers)

The house which is pink...Defining (Identify the house)

Students who study hard pass.Defining (Only those students)

Quick Check

1. My mother _____ is 50 is a doctor.

2. I need a phone _____ has a good camera.

3. London, _____ is in UK, is rainy.