Mum: Tom, can you help me in the kitchen?
Tom: OK. Shall I make the salad?
Mum: Yes, please, and can you do me a favour and take the dog out for a walk after dinner?
Tom: Sorry, I can't. I need to finish my homework. I'll ask Sue.
Mum: That's OK. I'll do it.
Tom: Shall I tell Sue and Dad it's time for dinner?
Mum: Yes, please.