Where did the "never end a sentence in a preposition" thing come from?

It may be strange to think that it was so recent, but nearly all of our English spelling and grammar rules date back to the 17th and 18th centuries, when standards were first introduced for the language. The rule that a sentence can never end with a preposition dates from this time as well, actually preceding standardized spelling by nearly 100 years. When public education became widespread in the 19th and 20th centuries, it was only natural that the still relatively new standards would be taught as part of a language education.

In general, resistance to the idea of not ending a sentence with a preposition comes from those who haven't taken the rule to heart, or who speak different English than they write. The difficulty with coming up with sentences that don't end with a preposition lies more in a case of word choice than syntax.

The example "which store are you inside of?" is an interesting one, given that the sentence actually ends with TWO prepositions. This is a fun game for us grammar nerds, to try to come up with sentences that end with as many multiple prepositions as possible while still scanning (reasonably) well. Two is pretty easy ("That's what we'll be talking about after."), three is more difficult ("What were you going on about before?"), and four is a real accomplishment (I'll leave that to the readers). None are correct, but it's a cute game.

Making a sentence ending with a preposition correct generally does not involve changing the syntax so much as changing the vocabulary to mean the same thing. For instance, "What store are you inside of?" could be said correctly as "Which store are you visiting?", which seems less awkward to many casual English speakers than the equally correct "In which store are you?"

“This is the sort of English up with which I will not put.”
as attributed to winston churchill
i doubt the german should try to explain in her own words so here is some more info
link

Okay. This is quite funny 'cause I read it once in a Readers' Digest joke book but I didn't really consider that it was a grammar rule. It goes like this:

For anyone who gets confused about proper grammar and style in writing, we offer, from the Internet, the following tip sheet, "How To Write Good":
-It is wrong to ever split an infinitive.
-Contractions aren't necessary.
-The passive voice is to be avoided.
-Prepositions are not the words to end sentences with.
-Be more or less specific.
-Who needs rhetorical questions?
-Exaggeration is a billion times worse than understatements.

Get my point? Remember that it came from a joke book.