Most of What You Think You Know About Grammar is Wrong
In Latin, sentences don’t end in prepositions, and an infinitive is one word that can’t be divided. But in a Germanic language like English, as linguists have pointed out, it’s perfectly normal to end a sentence with a preposition and has been since Anglo-Saxon times…
We can’t blame Latinists, however, for the false prohibition against beginning a sentence with a conjunction, since the Romans did it too (Et tu, Brute?). The linguist Arnold Zwicky has speculated that well-meaning English teachers may have come up with this one to break students of incessantly starting every sentence with “and.” The truth is that conjunctions are legitimately used to join words, phrases, clauses, sentences—and even paragraphs.
Perhaps these “rules” persist because they are so easy to remember, and the “errors” are so easy to spot.