Conversation is the process of activating similar-enough concepts in two people's brains, then using those activated concepts in coordinated action.
concepts
The theory assumes an associationist theory of thought 
:
* Concepts are "things" or "places" in the brain that can be active or quiescent.
* Concepts are activated by words. (Though not by words alone.)
* Activating one concept will activate "nearby" concepts.
* Thoughts are built by bashing activated concepts together. (Details left to the reader...)
conversation
What the brain is *for* is to cause the body to act in a way that's to its benefit (reproductive fitness and all that).
Conversation is the same thing, just indirectly. Your brain is moving your body in order to produce words...
... in order for another body to hear those words...
... so that the other body's brain will activate Compatible Concepts...
... so it will think useful thoughts and say them in the hearing of the original speaker's body...
... with the (unconscious) intention of activating concepts (or strengthening their salience in the current situation).
misalignment
Conversation may have multiple purposes, but one is certainly **to understand each other well enough** that those other purposes can be achieved. Or: the set of compatible enough activated concepts in the two brains have sufficient overlap to move forward.
Starting misalignment can be fixed by back-and-forth conversation.
However: it would be better for a speaker to realize on their own that they're not "getting their message across" (Conduit Metaphor) so they can correct the problem sooner and more efficiently.
One way is to watch the interlocutor's facial expression and body language.
head 'em off at the pass
But another solution is to learn from a vast flood of experience being misunderstood.
Imagine a small part of the brain that's devoted to thinking, "Oh, no, this is not going well. And in a way I've seen before." Someone with enough experience talking and enough consideration for the listener (so that the brain-part is activated) could head off misunderstandings and misalignment early.
I suppose that there are many such brain-parts that specialize in different kinds of conversational failures.
what about writing?
* The body exists in the physical world, so "feel nervous as you get near the edge of a cliff" helps with survival.
* Note that, in this theory, emotions like "nervousness" are concepts not different in implementation from abstract concepts like "freedom." (Here I follow Lisa Feldman Barrett .)
* Given that we're social animals, "feel nervous when disagreeing with a high-status individual" is as survival-relevant as being nervous at the edge of a cliff. Maybe moreso: a human deprived of the support of other humans has some serious problems, not easily solved.