Never say "f*king idiot." Say this instead. Polite English "I'm afraid you're not thinking very clearly." Formal English "You're being profoundly incompetent." Witty English "Ignorance has never looked so confident." Gentlemanly English "I fear the matter has slipped entirely past your comprehension.” Victorian English "I speak now not in malice but in earnest despair, for the conclusion you have drawn is of such astonishing simplicity that it grieves me more than I can readily convey; and yet I'm moved less to anger than to sorrow, so profoundly indeed that I find myself unable to discern whether your words arose from haste, from a species of naivety, or from a mind altogether too content with its first and poorest notion."