Interview with English Professor

I asked DR. S. the following six questions about errors he has encountered and how it affects the writer's credibility:
Question #1: What type of error bothers you the most?
A: Most annoying are careless errors because they indicate lack of effort or care. They tell me that the correspondent or student did not take the writing seriously (and by extension, did not take me seriously, since the writing was directed to me). I then suspect that the same laziness may extend to the quality of thought in the piece.
Question #2: Are there any styles of writing that make it difficult to understand what the author is trying to communicate?
A: I'm not sure styles in themselves are responsible for ineffective writing, but I do find that , more and more, especially on exams, student write in an outline style. the problem with abandoning a full prose style is that many of the connections, transitions, and steps in logic are omitted. In a sense the writer is suggesting that I already know what he or she is intending to say, and rather than make an argument, this person only needs to allude to some key words or concepts. I guess I am supposed to fill in the rest.
Question#3: How much does it affect their credibility if an author sumbits something with errors?
A: Careless errors always make me more dismissive of the work. Errors that do not seem to arise from lack of care suggest to me that the author needs more or better education.
Question #4: Is there a specific type of error you see a lot of English students make that could hurt their career later?
A: I think there is a tendency for English students to make their prose needlessly abstract. This is either to mask a thin argument or growing from the assumption that prose for an English class needs to be lofty or inflated. Actually I see both ends of that spectrum: prose that is too lofty and prose that is too colloquial. This is more a matter of style than of grammatical correctness.
Question #5: In general, do your students have a good understanding of grammar?
A: I think that many do and some (not a lot, but enough) don't. I am a little troubled by this, because some students obviously get it, and have enough practice to write coherent and grammatical sentences with little effort, but the ones who can't really can't. Many students don't recognize when they write sentence fragments, or when their sentences lack agreement or parallelism. For those students, writing for literature classes is a serious problem. Many students write run-on sentences and comma splices, and continue doing so regardless of how many times they are corrected. Lack of agreement is a nuisance, lack of parallelism and unclear pronoun reference can be serious impediments to clarity.
Question #6: Have the more common errors you see in students' papers changed over time?
A: The kinds of errors that I have seen increasing (and I am talking about errors rather than poor analytical skills, or poor skills of logic or argumentation) are errors in spelling that reveal, essentially, that students don't read much anymore. They show that the student has never seen the word written out, and therefore has no sense of what it should look like. An example from, say, Shakespeare class, would be when a student writes (as has happened once or twice each term for the last three or four years) that, for instance, Richard III murders his way to the thrown. While it may seem funny, I think a student who writes that has just never seen the work in print.