If I end a sentence with a preposition, how much trouble will I get in?

Is it ever all right to end a sentence with a preposition?

I tend to be a bit of a stickler about grammar, but there are some “rules” that make me crazy. The rule that you should not end a sentence with a preposition is one of them.

My daughter Rhianon’s ninth grade physics teacher assigned a group project to build and optimize a mousetrap-powered toy car. The students had to describe and quantify what was happening with acceleration, momentum, and friction. They were directed to turn in a very detailed interim report halfway through the project, and they were warned that the presentation and writing must be perfect.
They met often, worked hard, and turned in a ten-page report.

They ended a sentence with a preposition, and for that one error they received a D.

My husband Leo was livid. He wrote the physics teacher to say that he reviewed papers for the New England Journal, submitted by people from all over the world, and no paper was ever rejected for errors of grammar or usage. He said there was no better way to turn bright students off from science than this kind of nit-picking. I took a different tack. I consulted all the grammar manuals I could locate, and found that at least half of them proclaimed ending a sentence with a preposition to be fully acceptable.

Even armed with this research, Rhianon didn’t want to protest. But all through high school and college, she never took another physics course.

I think it was Winston Churchill who said, of the rule against ending a sentence with a preposition, “That is the kind of pedantic nonsense up with which I will not put.”

Someone else (please tell me who, if you know) wrote, “A preposition is a perfectly lovely thing to end a sentence with.”

So let’s all find some prepositions to end our sentences with. They should be easy enough to think of. A world without this ridiculous prejudice against prepositions is well worth striving for!