给定一段英文对话，请将其转换为问答形式。
"Person A: What did you do last weekend?
Person B: I went to a concert with some friends.
Person A: Oh, who did you see?
Person B: We saw Coldplay. It was amazing!"
Person A: What did you do last weekend?
Person B: I went to a concert with some friends.
Person A: Who did you see?
Person B: We saw Coldplay. It was amazing!