Polite questions and non-defining relative clauses

1.) Non-defining relative clauses give additional information about a person or thing.

Example: 

David, who comes from UK, is a very intelegent.

WE USE WHO FOR PEOPLE

WE USE WHICH FOR THINGS

THAT = WHICH= WHO

2.) Polite questions

Sometimes direct questions don't sound polite.

Direct: What's it about?

Polite: Do you know what is it about?

EXERCISE 1

Make polite questions

1.) I wonder if... ( tell me the time)?

2.) Can you tell me...( where/High Street)?

3.) Do you know...( what/our homework)?