Giving a Tip

Yusuke: Did you enjoy your meal, Oliver?
Oliver: Yes, it was delicious, thank you.
Yusuke: Great to hear! How was the service?
Oliver: It was excellent. The staff were very attentive.
Yusuke: That's good to know. Should we leave a tip?
Oliver: Absolutely, they deserve it.
Yusuke: How much do you think we should give?
Oliver: Let's leave 20%, that's usually standard.
Yusuke: Sounds fair. Here you go, Oliver.
Oliver: Thank you, Yusuke. Let's head out.