PE-59: Defining vs Non-Defining Relative Clauses
Two commas that change what a sentence means — how English separates essential information from extra information.
PE-59: Defining vs Non-Defining Relative Clauses
Read these two sentences slowly:
"My brother who lives in Tashkent is a doctor."
"My brother, who lives in Tashkent, is a doctor."
The first says I have several brothers, and I'm telling you which one. The second says I have one brother, and I'm adding a fact about him. Two commas changed the size of my family — and that is the whole lesson.
In this lesson you will learn
- Defining clauses — essential, no commas
- Non-defining clauses — extra, commas required
- The three rules that change with the commas
- which referring to a whole idea
1. Defining — it tells you which one
A defining clause is essential. Remove it and the sentence no longer identifies anybody. No commas are used.
The student who sits next to me is from Nukus.
Yonimda oʻtiradigan oʻquvchi Nukusdan.
Take the clause away and you get "The student is from Nukus" — which student?
2. Non-defining — it just adds a fact
A non-defining clause is extra. We already know exactly who or what is meant; the clause simply adds information. It always sits between commas.
Afsona, who sits next to me, is from Nukus.
Afsona, yonimda oʻtiradigan qiz, Nukusdan.
We know who Afsona is. Remove the clause and the sentence still works perfectly.
3. Three rules change with the commas
Defining (no commas)
- that is allowed ✓
- you can drop the object pronoun ✓
- no commas ✓
- The book (that) I read was good.
Non-defining (commas)
- that is forbidden ✗
- you cannot drop the pronoun ✗
- commas required ✓
- This book, which I read last year, was good.
4. When do you need commas?
- Is the noun already unique? A name (Afsona, Bukhara), my mother, this book → commas.
- Could the sentence lose the clause and still make sense? → commas.
- Does the clause answer "which one?" → no commas.
- When in doubt in speech, listen for a small pause — a pause means a comma.
Students who work hard pass the exam. (only those
students)
My best friend, who works very hard, passed the exam. (one person,
extra fact)
Qattiq ishlaydigan oʻquvchilar imtihondan oʻtadi. — Eng yaqin doʻstim, u juda tirishqoq, imtihondan oʻtdi.
5. which for a whole idea
In non-defining clauses only, which can refer back to the entire sentence, not just one noun. This is very common in good writing.
Sherbek arrived two hours late, which annoyed everybody.
Sherbek ikki soat kechikib keldi, bu esa hammani jahlini chiqardi.
Which = "the fact that he arrived late", not any single noun.
6. Common mistakes
My mother who is a teacher works at school 12.
My mother, who is a teacher, works at school 12.
Bukhara, that is an ancient city, is beautiful.
Bukhara, which is an ancient city, is beautiful.
The car, I bought last year, broke down.
The car (that) I bought last year broke down. (defining — no commas)
He failed the exam, what surprised us all.
He failed the exam, which surprised us all.
My friend, lives in Khiva, is coming tomorrow.
My friend, who lives in Khiva, is coming tomorrow.
Practice
1 Commas or not? Samarkand which is famous for its mosques attracts many tourists.
Show answer
Samarkand, which is famous for its mosques, attracts many tourists.
There is only one Samarkand, so the clause can only be extra information.
2 What do these two mean? (a) My sister who lives in Tashkent is a nurse. (b) My sister, who lives in Tashkent, is a nurse.
Show answer
(a) I have more than one sister — this is the Tashkent one. (b) I have one sister, and by the way she lives in Tashkent.
3 Correct it: Jasur, that won the competition, is my cousin.
Show answer
Jasur, who won the competition, is my cousin.
That can never appear in a non-defining clause.
4 Add a comment with which: It rained all weekend.
Show answer
It rained all weekend, which ruined our plans.
Which refers to the whole first half of the sentence.
5 Can you drop the pronoun? (a) The film that we saw was long. (b) That film, which we saw last week, was long.
Show answer
(a) Yes — The film we saw was long. (b) No — a non-defining clause always keeps its pronoun.
Key words — Kalit soʻzlar
- Defininganiqlovchi (zarur)
- Non-definingqoʻshimcha maʼlumot beruvchi
- Essentialzarur
- Extra informationqoʻshimcha maʼlumot
- Commavergul
- Uniqueyagona
- To identifyaniqlamoq
- To annoyjahlini chiqarmoq
- Ancientqadimiy
- To ruinbarbod qilmoq
🎯 Remember this
- No commas = essential, tells you which one.
- Commas = extra information you could remove.
- With commas: no that, and the pronoun cannot be dropped.
- Names and unique things almost always take commas.
- , which can comment on the whole sentence — never what.