Non-defining & defining, reduced & comment clauses

My grandfather, who's 87, goes swimming every day.

• Defining Relative Clause

• Non - Defining Clause

My sister, whose dog I'm looking after, is visiting a friend in Australia.

• Defining Relative Clause

• Non - Defining Clause

The house, which was built in 1883, has just been opened to the public.

• Defining Relative Clause

• Non - Defining Clause

My sister, who is married, is on holiday.

• Defining Relative Clause

• Non - Defining Clause

My brother who finished university this summer is spending the year travelling.

• Defining Relative Clause

• Non - Defining Clause

The house whose doors are shuttered is rumoured to be haunted!

• Defining Relative Clause

• Non - Defining Clause

The car that I drive is a red Mercedes. 

• Defining Relative Clause

• Non - Defining Clause

Canberra, which is the capital of Australia, is located at the northern end of the Australian Capital Territory.

• Defining Relative Clause

• Non - Defining Clause

He said he could speak French, ......................... was untrue.

• that

• which

• what

• whom

The reason ............ she can't meet you is that she's leaving today.

• why

• when

• that

• which