...anymore than: ignorant, illiterate, shallow, uneducated, uninformed, unlettered, unschooled, untaught, unthinking is a manifestation of "not consciousness (as in asleep)" - though it might be.
From the outside in, nobody can really tell for certain.
However, from the inside, everybody has the ability to tell for certain, though that ability must be developed before it can be of any particular benefit to one.
Just being "awake" is of no particular use except when the person understands something about that, and the "other thing", and why they are usually the "other thing", and hardly ever - if ever at all - "awake".
Once a person begins to learn from experience what's going on with their own evolving consciousness - from that of a child, to that of an adult, to that of an Awakened Man - they will very often find their use of language steadily improves with age, though their willingness to waste time and resources employing it will generally decrease, sometimes by "leaps and bounds". What that may mean is that, though useless and pointless internal chatter will decrease, hugely, their intentional output of "useful and pointed" discussion will increase. But, that is subjective of course. Your mileage may vary.
Now, of course, the Race or the Game can begin for Real - and one can leave the ordinary level of simplistic imaginary pursuits, worldly facts, figures and fake ideas, and enter the higher level of more complexity, more integration, more sophistication, more intelligence, and the most important of all - More Fun of the non-serious kind. Almost as much, if not more than one experiences during ordinary bodily sex, given the scope and magnitude of "epiphanic mind-music" generated by such personal examples (best, un-reported) that one might begin to accumulate on a regular basis. The Symphony is beyond the beyond.