http://www.askoxford.com/betterwriting/plainenglish/writingm...
"Here are seven non-rules imposed on writers that can be safely discarded...
(3) You must not end a sentence with a preposition."
"Here are seven non-rules imposed on writers that can be safely discarded...
(3) You must not end a sentence with a preposition."
"Prepositions are okay to end sentences with."