Funny how the simplest American swearing sounds wrong to my ears.
Just read this phrase. "I'll break your ass." In my mind you can't break an ass. I mean, it's soft and flabby. How do you break that? You can break a bone. In Russian there is a similar invective. "Надеру жопу." Which means "I'll beat you ass raw" or "I'll flay your ass alive" and so on. But not break. These strange-sounding phrases tend to flit out of my head as soon as I read them. Maybe one day they'll take root and I'll swear in my books like a proper American. Or maybe I'll invent some Russian-American pejorative amalgamation.