What a tempting website for folks who enjoy language. Some of the comments are spot on, whereas some of them are just spotty. Which commentators really and truly know the answer? Who knows. Who knows? I know. Then again, who knows who knows. Reality check please! There IS a definitive answer to this perennially entertaining though ultimately banal question. And the answer is:

It depends.

Sorry if that isn't satisfying enough to those who wish to employ "rules of English" as if English were math. But English ain't math. That's right. It AIN'T. Language, especially English, be it spoken or written, is all about nuance and intent. What intent? The intent that the communicator/writer intends. As to whether or not the communicator succeeds at communicating the intent effectively, that would depend upon two dynamic variables: The communicator and the audience.

If one wants to use the sentence "Who knows (?, ., !), then one had better know one's intent.

Think. Exactly what do you intend? "Who knows?" implies that someone may or may not have some sort of literal answer.

"Who knows." implies something rhetorically suggestive (which, yes indeed, is more like a CLAIM than anything else) and certainly DOES NOT imply that a question is literally being posed. And if one were to stick a question mark at the end of THAT, it would only serve to muddle the intent.

And, sorry, what Mrs. Shlonkenheimer told us when we were in the third-grade wasn't necessarily the whole story. Hey, SUCH IS THE AMBIGUITY OF LANGUAGE. Get used to it. (Yes, the caps are unattractive, but in lieu of italics...)

Whereas "Who knows!" implies that someone named "Who" knows something, and that the people who need to know what Who knows are either hearing impaired, having a noisy party, or standing a long way away. Whatever.

As for our sing-song vocal inflections? It all depends upon the meaning of what is being conveyed. Once more with feeling, that is entirely a function of intent. And anecdotal reports as to whether or not one's inflections drop or rise at the end of any given sentence that happens to begin with or in some way include a seemingly interrogative word such as "who" (or whatever) do not in themselves cut the mustard. Though, yes, if one is unsure of the intent of a sentence, it could be helpful to think of the sentence in terms of spoken inflection. But the drop-rise factor functions only as a less than definitive hint.

Just don't leave out context related considerations. Because the context is what's really going to allow you to accurately infer and comprehend the intent.

And if you yourself are the one responsible for writing the sentence, and you do not understand your OWN intent...eesh. You're in trouble. Please visit your local smartstore and get yourself an economy-sized bucket of INTENT, as that is what you are apparently in dire need of.

As for any intentionally limited and inherently repressive SPECIALIZED form of English (pseudo-English, quasi-English, semi-English) one might naively and earnestly refer to as "business English"? If all you want to do is write inter-office memos while remaining as generic and innocuous as possible, sure, just follow the paint-by-number rules. Remain invisible. Or possibly increase your chances of getting a promotion.

But seriously, just how much does the group of people sometimes referred to as the "business community" actually know about English? Or about language in general? Answer: Notoriously very little. That is, unless the business community in question happens to consist of exceedingly scholarly individuals who have put a lot of sincere effort into learning about English and language in general. Could that be the publishing biz? Maybe decades ago. But not lately. Nowadays those emperors tend to stroll about without a lot of clothing, just like almost everyone else. So, not surprisingly, hardly anyone notices the increasing nakedness.

This distinctively modern phenomenon is largely attributable to spell-checkers, auto-spell-checkers, and all other computer-powered crutches, aids, and cookie-cutter enhancements that allow people to delude themselves into believing that they're smarter, more sophisticated, and more talented than they actually are. Oh yes, and it's also attributable to privilege, cronyism and good old-fashioned nepotism. Ha ha! Come on, have a sense of humor. It's funny cuz it's true. And never be afraid to enlarge your vocabulary.

Okay, now let's use our imaginations to draw a Venn diagram that employs two circles. One circle contains the group of people who have chosen to pursue "business," especially those vocations that people choose when they really, really want to make as much money as they can with the least amount of personal effort and, subsequently and predictably, the greatest amount of harmful exploitation and outright lies...finance, banking, BIG business, and so forth. And the other circle contains people who are authentically scholarly regarding the subject of English and language in general. Got that? Great. Now carefully try to imagine the intersection of those two circles.

Next, go to your computer's Microsoft or Apple dictionary and examine it VERY closely. Really take the time to know it. Notice anything missing? If you haven't noticed anything missing, then you're not looking hard enough. There are many things missing. Both little things and big things. Both in terms of the words themselves and, more importantly, the CONCEPTS that the words represent. But it could be no other way, be it accidentally and as a result of practical streamlining, or strictly intentionally. Our electronic helpers have a variety of peculiar biases - some obvious, some not so obvious, and some undeniably ideological. And we are all assimilating those oversimplifications and biases to some degree whether we want to or not.

But that's just what our modern world is doing to most of us, with or without any amusing conspiracy possibilities. As our standards crumble (and they are crumbling) under the weight of an increasingly simplistic and incompetent populace, one can count on our collective standard of deviation to decrease while the sharpest edge of our bell curve is dulled. The brightest outliers begin to dwindle. Less and less variation. Duller and duller. (Now THAT'S math. And I'm a wiz at math.) And that's how the process of dummying-down works in real life, just in case you've ever wondered. It's an entirely predictable and common process of domestication. And, unlike evolving a cool trunk or a set of funky wings, the subtle negative changes that relate to mental competence (and all manner of congenital behavioral disorders, autism, etc.) can easily occur over relatively short time spans. Really, just a few generations can yield quite measurable negative shifts. And we're already way beyond just a few.

And the computer is the most brilliant Skinner box ever invented. (Study behavioral psych, and any other psych by which you may be psyched...it is not just a lot of hoo-joo and baloney.) And we are the pigeons. But we don't mind being pigeons because our new toys have been carefully designed to compensate for our increasingly remedial inclinations while simultaneously lulling us into a satisfying state of unjustified confidence.

So what if most of us do not like thinking about how easy we are to manipulate. (Please note the ABSENCE of a question mark.) The EZ rule could not be simpler: The simpler we are, the easier we are to manipulate. And our machines are both allowing us and encouraging us to become simpler and simpler.

Ironically, yes, the members of the "business community" (the banking-financial-political-newz-tainment CHUM bucket) tend to be unscholarly. Very much so. These laughably transparent characters tend to be rather lazy and low caliber. But they (and especially the folks they hire to do the dirty work) are not dunces regarding the subject of manipulation. Quite the opposite. "Business" is all about manipulation.

But an even deeper irony of all this jazz (and an irony that perfectly befits this particular comment thread) is that the English language is so inherently potentially subversive, with its almost absurdly unnecessary (yet necessary!) subtly complicated tenses, idioms, idiosyncratic possibilities, and its highly evolved, flexible ability to absorb and convey concepts.

But don't worry. We're all being manipulated into using English in ways that are increasingly simplistic and non-subversive. We are being pigeonholed. The folks who believe that they OWN US (and there are such people) do not want us to exercise our critical thinking skills. And they're becoming quite adept at dummying-down the English language towards that end. And as our ability to employ and comprehend linguistic subtleties deteriorates (and it is deteriorating), we shall continue to become more and more vulnerable to manipulation.

Would anyone care to argue that the "business community" is unbias enough, responsible enough, and ETHICAL enough to make da compooters and all da massive FUN-FUN mass-media newz-tainment language stuff reely cool distracting and in a nice happy way 4 short attention spans that has nothin ta do with all that comp'icated psycholojickle stuff? Reely? U think? Shur. What he said. That a good argum ent. It worx fer me LOL (Insert dancing pickle emoticon HERE.)

All I know is that I'm confused by all these comp'icated rules that are not really rules. I don't want to think about what I intend. I just wanna have fun. That's what life is all about, doncha know. (Again, no question mark.) And isn't it nice to have so much help figuring out how to have fun? And how to do stuff? Duhh Yup! I want REAL rules. Rules that will tell me exactly what to do. I want rules that will bully me into submission. Who cares about the myriad, subtle variations of meaning and INTENT that one encounters in a vital, thoroughly nuanced written language? I don't! And what's the point of trying to know anything when one can just sit back and enjoy the ride? Who knows.

By the way, this comment is completely apt. From start to finish. Plus it was fun to write. And it didn't even take a lot of time. I'm quick. (Please pardon my typos.) And I may even be slightly above average and somewhat knowledgeable.

Sure, some folks may complain that it's too long, or too comp'icated, or that they don't like my TONE. Just like some folks go around encouraging everyone to always put a question mark at the end of a sentence that begins with the word "Who" simply because it begins with the word "Who." But those folks are just plain WRONG. Do not heed their bad advice. The most accurate answer to the question posed is anything but ambiguous. It is about thinking FREELY. And it IS knowable. Who knows? Not everyone equally. But to one who knows, the answer is as clear as an un-muddied lake...as clear an azure sky of deepest summer. You can rely on me ;-) I am a fount of accuracy.

In the sage words of another thoughtful violinist who was better at math than I could ever dream of being: "Make things as simple as possible, but not simpler."