I've read advice before about the use of certain words when writing from specific perspectives. If writing from the viewpoint of an uneducated boy, don't let them know words that are beyond what reality would allow. However, there are some situations in which there is simply too much that the viewpoint character should not know, and I have no idea what alternatives to use to replace such words or phrases. In a piece I am working on, humans and the planet Earth do not exist in the known world. Since I am writing from limited third-person perspective, it makes no sense for my characters to use the words 'humanoid', 'humane', or even 'mankind.' Curses such as 'what the hell', 'what on Earth', and 'sweet jesus' (yes, really) are all out of the question as well. Has anyone else fallen into a situation like this before, and if they have, what sort of solutions did you use to replace those words and phrases?
I once read a story, set in a world of intelligent equines, where a sign on a door said AUTHORIZED PONYNEL ONLY. I would suggest not doing something that blunt, but it can work on a smaller scale. For instance, if your species is called Gurans, "humanoid" becomes "Guran-like" and "inhumane" becomes "un-Guran."
If you're writing in a non-existent world you're presumably using all kinds of English (or whatever language you're writing in) words that simply wouldn't exist in that world. Except in circumstances where it is really jarring I wouldn't worry too much about this.
I wrote a story set in a world where there was no taboo about sex of any sort and no real religion, either. Which made it hard for characters to swear! I just tried to figure out the roots of the swear words I wanted to use, and then transfer those roots to a different culture. They were very militaristic, so I made up a lot of "you rust-stain!" "By my sword" type words. I remember Ann McCaffery doing something similar in her Pern books. "By the first egg," was a big one, and I think there was something about threads, too.
Totally off-topic: @BayView, you just time-traveled me back to my 8 year-old self where, for a short time, I made a small fetish of using Ann's Pernian swears and oaths. My poor parents. They had no clue what to do with me.
Thanks for the tips, I'm still working out a lot of my not-on-Earth idioms and curses. Pernese Sayings, Proverbs and Maledicta
Humanoid: - Bipedal, or something that adds up to "four-limbed and upright". Or, assuming that the creatures that speak this language are humanoid, various things that add up to "like us" or "normal." Humane: - You could just expand to the traits that this is supposed to mean--kind, empathetic, etcetera. Mankind: - You could coin a word for this or, if there is thought to be only one sentient race, you could go with "sentients" or something similar. What on Earth: - Well, presumably the planet has a name. If the beings have expanded past their planet, there's "what in creation", or there's the Firefly use of "the 'verse." The other curses would presumably come out of the culture.