Situation 1: Your friend is thirsty.
A: You look a bit pale. What's the matter?
B: I'm really thirsty. I've been playing outside for hours.
A: How about going to the shop and buying some water?
Situation 2: Your friend is sad.
A: You seem down. What's wrong?
B: I'm sad. I didn't get the part in the school play.
A: Oh, I'm sorry to hear that. Let's sit down and watch a funny movie to cheer you up.
Dialogues for two chosen situations are above.