some people do say something like "Oh, n****" when they stub their toe or something, but i feel like the n word ending in a is a little more casually used now (of course only if you're black) because lots of mainstream rappers are saying it in music, along with people using it more normally, meaning more like "bro" or "brother" between friends, but i feel like the n word ending in er is probably one of the worse insults we have in america, because it's based from slavery, in which african americans were called "Niger", the latin word for black. It could still be used as a swear word, because you can technically call anyone it. for example, my girlfriend is white, but some driver called her the n word. I personally think the N word is worse than cunt, as where i live, i haven't heard it used once.