Martha: Hi! Can you cover the afternoon shift?  
George: I have a day off. I really need it.
Martha: I know and I am sorry to bother you on your day off but we need you. Karen called in sick so the remaining staff are struggling. 
George: I see. It’s the second time this month, isn’t it? 
Martha: Don’t get me started.. I have to talk to her as soon as she’s back at work.
George: Look, I’ve got some stuff to do this afternoon. Can you try Anna?
Martha: I did but couldn’t reach her. I’ll give you a whole day off any time you want. On Friday perhaps?
George: Fine. Count on me. But it’s only because you ask me nicely ;)
Martha: I really appreciate it.
George: See you later then.
Martha: See you and thank you so much!
Karen called in sick again and Anna is out of reach, so Martha needs George to cover the afternoon shift, even though it's his day off. George agrees to Martha's request in exchange for a whole day off another time.