Talking on the phone, or to the phone?

Question

I want to know whether I can ask a question like

Have you finished talking on the phone?

or should it be

Have you finished talking to the phone?

Answer 1

I would go with

Have you finished talking on the phone?

because it has the meaning of

Have you finished talking (to another person) on the phone?

Your other sentence

Have you finished talking to the phone?

means that someone is talking to the physical object that is the phone - not to another person.

In this context, the preposition "to" is used to show who or what is being talked to.