As the legend goes, the "never end a sentence with a preposition" rule was actually a revisionist prescription at some point in the (relatively recent) past. The goal was to make English more "elegant" and Latinate in its usage. This prescription actually flies in the face of English's origins. English did not derive from Latin, even though it borrows a lot of words and phrases from Latin. The rules of English grammar do not follow those of Latin, nor should they.
Modern English is a hodgepodge of a variety of languages. The history of the language is really quite interesting, and I suggest anyone look into it if they have interest. If you try to read pre-Norman English today, you'd be hopelessly lost (unless you were previously trained to do so). Take a look at the original text of Beowulf and compare it to, say, the Canterbury Tales. The Canterbury Tales is a rough read; Beowulf is unintelligible.
True, although the rules of grammar and construction have not changed as dramatically as the vocabulary, spellings, or pronunciations have. Gramatically and syntactically speaking, English is still quite Germanic. That's why it is (supposedly) easy for a native English speaker to learn Dutch or German; their conjugations and sentence structures are more intuitive to us than those of the Romance languages.
