There’s a general belief that a great talker is also a great communicator. That might be true, and yet I find that most often it is not.
The way I see it, there are three core qualities of a great communicator (that a great talker not necessarily has).
First, great communicators craft their messages carefully. I mean this in the broadest possible way. A good framework to look at it through is Grice’s maxims: quality (a message that is true), quantity (a message that is no more than what required), relevance (a message that is pertinent to the discussion) and manner (a message that is orderly, polite and clear).
Then, great communicators are consistent in their messages. They are not afraid of repeating, as they are aware that different people absorb information at different paces. Furthermore, having the message well-crafted allows them to experiment with channels and formats in ways that benefit the spreading of the message in the long term.
Finally, great communicators have profound understanding of their audience. This is also true in a broad way: they know who they are communicating with before the communication actually happens; they are awake and aware to signals from the audience while the communication is undergoing; and they are capable of redesigning (without losing consistency), learning from feedback and sentiment they perceive after the communication is over.
If you want to be a great communicator, talking a lot and well is not enough. Establishing a relationship aimed at some type of change is much more important. And much more complicated.