A nice, tug-at-the-heart-strings conclusion, USMC! Quite relevant with regards to the overall education, and development, of each and every one of us, but of questionable relevance to teachers and learners of foreign languages. In any event, that's not reason why I have responded.

Graemer's singular query trebled as a result of one forum member suggesting the use of "which" and another suggesting the removal of "each".

Whether "do" or "does" is used, I think there is very little risk that any reader would / could misconstrue the question. Likewise with "what" v "which". In both cases it's really only a question of strict adherence to grammar rules. As I have already expressed, I believe that deletion of "each" could cause a reader to misconstrue the question.

So, two of the three "issues" are not important to the writer's goal of readers understanding the question. What conclusions can be drawn? Perhaps, "English is grammatically overly complicated." or "Strict observance of English rules of grammar is not always necessary."? Ahh, but the latter raises the question, "How can a learner know and understand when "strict observance" is not necessary?".

The English language is in dire need of an overhaul. When, and by whom, I have no idea! I am quite sure (and to be honest, quite relieved) that it won't happen during the remaining years that I'll be teaching English. I will admit to disliking some of the changes that seem to be occurring at present; "bad" becoming a noun, "s" being added to anyway, "couldn't care less" commonly expressed as "could care less" (That one defies logic in my mind! If you could care less that means that you do, in fact, care about something, right?).

So where does that place me? Exactly where I am; "teaching" IELTS to students who aspire to study abroad wherein the students need to have a fairly good command of grammar.

As for students who want or need (even if such wants and needs are dictated by school administrators) a very broad, very general command of modern-day English usage, I think that the fresh-out-of-college kids, backpackers and anyone else who has a native speaker-like command of English can fulfill such requirements.

As my dear old mum used to say, "There's a place for everything and everything should be in its place!"