"Teachers teach from manuals." The logical conclusion is that you meant all teachers. If you didn't, you would have said, "Some teachers teach from manuals." or "Twenty percent of teachers teach from manuals."

Mark, don't assume we know all your thoughts. We can only know the points you are trying to make by the choice of words you use. This forum is so limited for this type of discussion, so everybody must be very careful how they word their statements. Taking two days to ask what you mean just takes too long.

However, in the spirit of asking (like you requested) - I'm interested in how you arrive at your "20% rule". Please cite some examples, as specific as you can. Please don't broad-brush it like you typically do, because your statment, by default, insulted 80% of the readers of this website.