Fundamentally mindfulness is about observations, participating. And communicating, all with awareness and a non-judgmental attitude. This is by no means easy achieved, but training make us better. Even thinking of my thinking is mindful awareness. Noticing my thoughts is the cornerstone of zen.
While observation and participating should be noticing thoughts drifting without concepts, which in itself by no means is an easy task, mindful communication is different. By trying to convey observations and experiences we are forced to use a language which implies conceptualizing. The trouble then is that concepts not fully can convey such experiences without contraining them into a smaller context and frame than the original open-minded experience.
I am a professional lecturer, and the more mindful I get, the more I become aware of the limitations of the spoken language. Framing a much wider reality is both a necessity and a consequence of the inherent limitations in all sorts of languages. Mindfulness makes me, presumably, a better lecturer, but also makes me more aware of my communication contrains.
But also in life in general I believe we same difficulties. We conceptualize, both in thoughts and in spoken words. We categorize, we catalogue our experiences, our views of others and our surroundings. And by that we both constrain reality, but more seriously also judge in a mindless way. So it is not a matter only of our communication with others, it is also a matter of our inner dialogue. We conceptualize, constrain, and by that also judge.
There is not much we can do about these limitations of language) apart from in a mindful way being aware of of them. And we should also mindful be aware of our tendency to conceptualize and constrain in our inner dialogue. We become what we think, and since thinking also is about concepts in an inner dialogue, the constraints in our inner conceptualizing also needs our focused awareness.
Mindful communication, whether outer or inner, is no simple task, but still is essential in every human life.