We talk to think. There are times when we had an idea, but are unable to clearly articulate it, we would try to talk with somebody to find the right words. Sometime when there are nobody convenient, talking with ourselves serve the same purpose.
We talk to release our emotions. When we are sad, we talk to loosen up ourselves, to release our burden. When we are angry, snapping at somebody does make us feel better.
We talk to amuse ourselves. When I was young, there was this question and answer session by my principal, and I can’t help but asked him “Can we go now?”
And of course we talk to convey information.
Understanding why people talk, help us to avoid misunderstanding, somebody talking to think is probably not trying to imply anything. It is often better to help them complete their thoughts than reacting to their words.