main clause, who + clause, main clauseUse who after a person when the clause adds extra information, not identity.
Non-Defining Relative Clauses
B1Non-defining relative clauses add extra information to a complete sentence. They use commas, and you keep the relative word.
What you'll learn
- Add extra information with who, which, where, and whose.
- Use commas to separate extra information from the main sentence.
- Keep the relative word in extra information clauses.
- Use whose to connect an owner to extra information.
- Recognize when the clause is only extra information, not identification.
Structure
main clause, which + clause, main clauseUse which after a thing or idea when the clause is extra information.
place, where + clause, main clauseUse where for places when you add a comment about that place.
noun, whose + noun + clause, main clauseUse whose to show possession inside the extra information clause.
Build a sentence
Noun type
Relative word
My brother,who is a doctor,lives here
My brother, who is a doctor, lives here.
Use who for people when the clause adds extra information.
When to use
People
Add a comment about a person you have already identified. My brother, who is a doctor, lives here.
Things
Add a detail about a thing that is already clear. The new phone, which was expensive, is already broken.
Places
Add extra information about a place name or known place. Paris, where Lisa studied, is very busy in summer.
Markers
whowhichwherewhose
In contrast
vs defining-relative-clauses
Defining relative clauses identify exactly which person or thing you mean. Non-defining relative clauses only add extra information, so they need commas.
vs omitting-relative-pronoun
In defining clauses, the relative word can sometimes disappear. In non-defining clauses, you keep the relative word.
Common mistakes
Wrong
Tom, who teaches math lives next door.
Correct
Tom, who teaches math, lives next door.
The clause who teaches math is extra information, so it needs commas on both sides.
Wrong
My uncle, lives in Miami, is visiting tomorrow.
Correct
My uncle, who lives in Miami, is visiting tomorrow.
A non-defining clause keeps the relative word. You cannot drop who here.
Wrong
Anna's laptop, who is brand new, keeps freezing.
Correct
Anna's laptop, which is brand new, keeps freezing.
Use which for things, not who.
Wrong
Mr. Brown, who has son works here, is very friendly.
Correct
Mr. Brown, whose son works here, is very friendly.
Use whose to connect the owner and the noun inside the clause.
Wrong
The employee, who speaks Japanese, can help you.
Correct
The employee who speaks Japanese can help you.
Here the clause identifies which employee, so it is not extra information and commas are wrong.
Common misconceptions
❝ If I remove the clause, the sentence becomes wrong. ❞
With non-defining relative clauses, the main sentence stays complete. The clause only adds extra detail.
❝ Commas are just style, so I can skip them. ❞
In non-defining relative clauses, commas show that the information is extra. Without them, the sentence reads incorrectly.
Skills in this rule (5)
ADD_EXTRA_INFO_WITH_WHO_WHICH_WHEREw5Add extra information with who, which, or where
Use a non-defining relative clause to add extra information about a person, thing, or place. The main sentence is already complete without this extra part.
USE_COMMAS_FOR_EXTRA_INFOw5Use commas around extra information clauses
Put commas around a non-defining relative clause because it adds extra information, not core identity. If you remove the clause, the sentence still works.
KEEP_THE_RELATIVE_WORDw4Keep the relative word in extra information clauses
Do not drop who, which, or where in a non-defining relative clause. The clause needs the relative word to connect smoothly to the main sentence.
USE_WHOSE_FOR_POSSESSIONw4Use whose to show possession
Use whose when the extra information clause shows that something belongs to someone or something. Whose links the owner to the noun that follows.
PICK_EXTRA_INFO_MEANINGw3Recognize when a clause gives extra information
Choose a non-defining clause when the listener already knows exactly which person or thing you mean. The clause only adds a comment or detail.