B1. - And could you give me...
A1. - Sure. Take a seat.
A2. - ...Could I ask you...
B2. - Of course. What is it?
A2. - Could you tell me...
A3. - ...Can I ask you a favour?
A3. - Could you help me...
B3. - What's the problem?
A4. - Dad, could I borrow...
A4. - ...Can you lend me some?
A4. - ...Can I have five pounds?