For me there’s two separate participants, a ‘talker’ and a ‘listener’. My mind identifies more with the talker, because that’s the one that has agency. Since there are two participants, both of which are me, I talk in 1st person plural (‘we’ve got to do …’, 'we thought about this earlier’). I stopped being afraid of being alone after I started having an internal dialogue around the age of 11, since having a second participant in the conversation meant I was always in company.
It depends, if it’s a problem I’m trying to solve, if it’s a presentation that I’m going to do, if I need to communicate with someone. Like I thought about responding this, while trying to observe how it works.
Normally there are a lot of monologues happening at the same time and I’m probably listening to music too, so I’m like 30 seconds thinking about something, pass to another something and then the good part of the music comes. I took ADHD meds once and damn, this completely disappeared hahahaha.
But, depending on the thing, if it’s a concept I’m trying to tackle, normally it’s just me alone passing through it, its ramifications, consequences, basis, etc. If I’m trying to talk to someone, I like to imagine them and interact with myself playing as them. Sometimes it’s like yours, two of me separated from me “debating”.