From Longman Dictionary of Contemporary EnglishI would prefer it ifI would prefer it ifspoken a) PREFERused to say that you wish a situation was different Sales have gone down, and obviously we’d prefer it if that didn’t happen. b) NOT DO somethingused when telling someone politely not to do something I’d prefer it if you didn’t smoke in front of the children. → prefer
Examples from the Corpus
I would prefer it if• I'd prefer it if you would not insult my friends.• I would prefer it if we had a bigger house, but we can't afford it. 