I owe you one.
Speak as Wendy
Speak as Carrie
Carrie: Sure. What do you need?
Wendy: Can you give me a ride to the airport?
Carrie: Is there something wrong with your car?
Wendy: No. I just don't want to leave my car at the airport for two weeks. Also, I would ask my husband to take me, but he has an important meeting at that time.
Carrie: It's fine. I would be happy to take you to the airport.
Wendy: Thank you so much. I owe you one.
Carrie: What time do you need to leave?
Wendy: I need to leave by 4 pm.
Carrie: Okay. I will pick you up a little before 4 pm.
Wendy: Thanks again. I really owe you.