Defining and Non-defining Review

Defining clauses identify; non-defining add extra information.

Examples

• The man who called is my boss.

Key rules

• Defining clauses give essential information with no commas (The man who called is my boss)
• Non-defining clauses add extra information and use commas (My boss, who is 50, called)
• That can replace who or which only in defining clauses
• Which can refer to a whole clause

Common mistakes

• My brother, that lives in Rome → My brother, who lives in Rome
• The man, who called, is my boss → The man who called is my boss