I always imagined a really anal police negotiator yelling “Out, up with your hands, come!”
First thing I thought of when I read the thread title:
The issue with “where is it at?” is that “at” is redundant.
Though I would find it odd if someone said “Where’s it?” If you use the contraction, the addition of “at” sounds better to me.
A word that appears at first glance to be a preposition isn’t necessarily a preposition:
on: adverb
31.
in, into, or onto a position of being supported or attached:
Sew the buttons on.
Now don’t you start! Yes, of course. But the person who would use “whom” would probably also say “With whom are you going” in the first place. 
Yes, clearly in English it’s not only possible but common to end a sentence with actual prepositions, not just verb particles from phrasal verbs.
[ul]
[li]For starters, you can wipe that smile off your face.[/li][li]First, you can wipe that smile off your face.[/li][/ul]
To answer the OP, I’m somewhat surprised that there are still so many people who believe you can’t end a sentence with a preposition (or split an infinitive, for that matter). As others above me have pointed out, this “rule” has been authoritatively debunked many times.
I found out last week that on my phone, when I do a double space after typing a word, it puts a period after the word, then a space. The next word is capitalized, all automatically.
That’s fairly easy to correct if you wish to follow the “rule”" I will not put up with this sort of English.
How about the little boy complaining about his parent’s choice for a night time story.
“Why did you bring that didn’t want to be read to out of from up for?”
I’ve heard it was a book about Australia
“Why did you bring that didn’t want to be read to out of from about ‘Down Under’ up for?”
But that’s really a cheat as Down Under is a noun there.
As far as the PERIOD-SPACE-SPACE rule goes, that’s a holdover from learning to type on a typewriter. It’s archaic now, and not needed since the only reason for doing so was typographic in nature. That is, before digital typography was able to automatically put in the proper amount of visual space between sentences at the end of a period, typing teachers taught you to add an extra space after the period to pad out the space between sentences to compensate for the lack of ability to kern on a typewriter.
While I understand there are many still out there that are too used to typing this way, it’s entirely unnecessary in this digital day and age. It has nothing to do with grammar.
In grammar and in life, we often feel constrained by rules that do not, in fact exist- that are not truly rules at all. Sometimes we take those bogus rules more seriously than genuine rules.
Allegedly, it was Winston Churchill who said it, but probably not.
Yes, it’s is the redundancy that makes it wrong*, and annoying if you translate.
“Where is the library at?” The ‘at’ is unnecessary. “Where is the library?” is better, especially if you translate it into spanish.
" ¿Dónde está la biblioteca?" not “¿Dónde está la biblioteca…a?”
Same with “You can wipe that smile off your face to start with”, the "with is unnecessary and redundant, “You can wipe that smile off your face to start” makes just as much sense. The ‘with’ doesn’t add anything grammatically, it just makes the phrase a bit more hostile, which may be the intent, it is easier to snarl on the word ‘with’ then the word ‘start’.
Once again, doesn’t work in spanish “Puedes borrar esa sonrisa de tu cara para empezar.” not “Puedes borrar esa sonrisa de tu cara para empezar…con.”
My rule of sentence ending prepositions is if the sentence works without the preposition at the end, just don’t use it. If the sentence needs that proposition to make sense, and it is clunky to restructure to move it to a more appropriate (pedantic grammatically speaking) place, I leave it.
*by “wrong” I do not mean wrong wrong, but wrong from a standpoint of pedantic grammar wrong.
One of William Safire’s first fumblerules of grammar was “Never use a preposition to end a sentence with.”
Yeah, a lot of that list is just abject nonsense. His first item was “remember to never split an infinitive.” (Yes, I understand it’s lighthearted humor, and each rule is an example of itself, but my assumption is that the list is such because he believes those rules should be followed.)
No, I think Safire liked to have fun with the English language. He probably would have said, “Know the rules forward and backward- and ONLY then are you qualified to decide when it’s okay to break the rules.”
I think Safire would have said, "Develop an ear for the English language- and when following a rule makes a sentence sound clunky, break the rule. Refusing to split an infinitive often make a sentence sound awkward. If so, use your discretion and break the rule because you think the resulting sentence is neater and clearer. But never break a rule just because you’re unaware of it. "
But the thing is, it’s not even a real rule to begin with.
Of course, the split infinitive rule comes from Latin, where infinitives are one word and can’t be split. There is no logical reason why it should be a rule in English; people just thought Latin was better.
Grammatical “rules” of this sort are usually silly. The purpose of grammar is to facilitate clarity and meaning; there is nothing to be gained by a rule saying you can’t end a sentence with a preposition. There IS a lot of logic behind, say, ensuring that sentences are not fragmented. Sentence fragments can leave the reader confused as to what the hell is going on.
Very surprised so many people had opinions and input on something like silly prepositions. Lots of great responses!!!
I’m very surprised nobody has suggested a better title:
“Who knew that a preposition was something you could actually end a sentence with?”
And this, again, brings us back to a point which has already been made: The only unbreakable rule is clarity, unless you intend to be unclear.
More seriously: Humans are grammatical animals. We have a region of our brains, Broca’s area, concerned with producing language and, more importantly, producing grammatical language. Someone with Broca’s aphasia, also called expressive aphasia, which is aphasia linked to damage of Broca’s area, know words but they don’t know how to put them together in sentences and don’t know how to use grammatical function words, such as “of” and “in” and so on. The point is, it takes brain damage for a human to completely lack grammar; speaking like a poor person or a minority doesn’t qualify.
And humans usually speak to be understood. Most human utterances are grammatical and clear to the intended recipient, unless the person intends to be unclear. Humans have two whole regions of the brain dedicated to that (in addition to Broca’s area, there’s Wernicke’s area, concerned with understanding language) and we spend our lives honing these skills. Therefore, the real rules of grammar are unconscious, encoded in parts of the brain dedicated to those kinds of processing, and must be researched using all the techniques of scientific investigation before actual linguists can write books about the grammars of specific dialects of a specific language.
Peevers try to short-circuit this, take the easy route by demanding that their “prescriptivist grammar” is just as real as actual grammar, descriptivist grammar, which they deride as ungrammatical whenever real life refuses to bow to their whining. They lack the intellectual rigor or, really, the patience to advance an actual field, and they cover for their laziness and incompetence with endless condescension towards the people who know more than they do.