In Fundraising, Your English Teacher Gets an ‘F’

Sentences that end with prepositions
On this rule, I’m with Winston Churchill. It’s said that once, on seeing some fussy and unnecessary edits made to something he wrote, he thundered something to the effect of, “This is the sort of bloody nonsense up with which I will not put.”

There’s actually a reason for this rule: If you end your sentence with a preposition, you’ve left the prime emphasis spot — the last word — with a piece of grammatical scaffolding.