I once had a manager whose level of literacy was lacking to the extent that he would nearly always return my technical reports with sections rewritten such that they became either ungrammatical, or would convey an inaccurate notion to most readers (due to poor wording).
One of my colleagues would often describe that manager as being illiterate, or (if he happened to be feeling magnanimous), semi-literate.
I was wondering, are there any better words or phrases to describe someone who is prone to such things as grammatical errors, spelling mistakes, tautologies and misinterpretation of (relatively) common words/terms?
In other words I'm looking for descriptive terms, or even colloquialisms, that would apply to someone who is particularly poor at expressing themselves in writing.
As an aside, I am also interested in what words could be used to describe the opposite quality... I.e., descriptors for someone who is particularly articulate and eloquent in their writing style, and good at finding the most concise, and effective way of conveying even the most complex ideas. (Perhaps something along the lines of well-spoken, or well-versed in the art of written communication?)