Telephone language and phrases

Good morning/afternoon/evening, York Enterprises, Elizabeth Jones speaking.
Who's calling, please?

Introducing yourself

This is Paul Smith speaking.
Hello, this is Paul Smith from Speakspeak International.

Asking for someone

Could I speak to John Martin, please?
I'd like to speak to John Martin, please.
Could you put me through to John Martin, please?
Could I speak to someone who …

Explaining

I'm afraid Mr Martin isn't in at the moment.
I'm sorry, he's in a meeting at the moment.
I'm afraid he's on another line at the moment.