第一句：Who are you calling, please?
请问您要找哪位？

A: Who are you calling，please?
甲：请问您要找哪位？
B: Can I speak to Mr. Geller?
乙：盖勒先生在吗？

第二句：Who's calling, please?

请问您是哪位？

A: Hello，this is BM Mike. Who's calling，please?
甲：你好，这里是BM公司，我是迈克。请问您是哪位？
B: Hello. Tony Baker speaking.
乙：你好。我是托尼?见克。

知识扩展：

(1)
Anyone in particular?
您要找哪位？
Who in particular?
您找哪位？
Who would you like to talk to?
您想要找哪位？

(2)
Hello! This is Jim. Who's that?
您好，我是吉姆，请问您是哪位？

Hello，this is Tom calling, to whom am I speaking?
您好，我是汤姆，请问您是哪位？
Who's that, please?
请问您是哪位？
May I ask who is calling?
我可以问下您是哪位吗？