B1 GRAMMAR · CLAUSES · B1–B2
Defining vs non-defining relative clauses
Relative clauses add information about a noun using who, which, that or where. A defining clause is essential; a non-defining one just adds extra detail.
See the difference
A
Defining
essential; no commas
The man who called is my boss.
打电话的那个人是我老板。
B
Non-defining
extra info; needs commas
My boss, who is kind, called.
我老板（他很和气）打了电话。
Practise it
Q1 The book ____ I bought is great.
Q2 That’s the café ____ we first met.
Q3 She’s the teacher ____ helped me.