I'm working on a story that deals with the split between North and South Korea, and something I have been focusing on lately is the language differences between the two nations. One thing I have learned is that when South Koreans hear people from the North is that they tend to speak in a way that is considered rather dated, since the country split in the fifties and the North has more or less completely isolated themselves from South Korea and the rest of the world.

So North Korea was never exposed to the changes in language in South Korea, leaving them sort of stuck in the fifties.

So what I need are some rather dated English words, or even words that are considered especially modern-sounding (slang and the like).