Languages have such wonderful little idioms. For example, in Italian when you want to say “damn!” you say “che cavolo!” That’s literally “What a cabbage!”
English has some quaint expressions as well. In New England, “wicked” is positive. “Wicked good” is several notches above good, and “Wicked awesome” is about as good as you can get.
Mike: “Did you see the Sox game last night?”
Jim: “See it? I was there! Beating the Yankees 12-0 was wicked awesome!”
In creating different cultures (I’m looking at fantasy and sci fi writers specifically), keep in mind the strange things that might not be translated literally. It could be very interesting to have a character translating from his language to another, or even from one area of the country to another, and having a complete miscommunication.