Most human swearing and cursing is based on either bodily functions (notably reproduction and waste elimination) or on religion. In an alien society where there are no taboos along those lines and where there is no religion, what might take the same place as words used for emphasis? These are words to use in anger, to attack other people, or to add emphasis to points. What do these aliens say when they accidentally trap a tentacle in the door?
For more information on the aliens:
They evolved from 6-limbed octopus-like creatures that moved onto land and developed two strong walking legs and 4 manipulator tentacles.
They were/are scavengers and are able to eat pretty much anything, so have no real disgust aversions for bodily waste/rotting carcasses/etc.
They did have religion but have since moved away from it and are now almost completely atheist, the last "believers" died many generations ago.
Technology level is similar to ours, maybe twenty to thirty years ahead of ours. They have some people on their moon and more in orbit but most space exploration is automated probes.
All members are hermaphrodites. Reproduction is usually done through asexual means, they can mate and produce offspring with share DNA but there is no particular urge to do so and it's not considered strange either to do so or not do so.