The Perils of Using Slang in Another Language

Slang, idioms and colloquialisms, they're all just kind of in a vacuum for foreigners. Even if we understand the meaning perfectly, knowing what feeling or image it evokes and when is proper to use it is a pretty nebulous thing to understand! For instance, the phrase, "fucked up." This is not something we'd usually use right off the bat with our boss or the grocery clerk. Or the phrase, "hotter than hell." For me, it makes me think of an older person from the South.

I got a new conversation partner recently, and he wrote in a message, "You ain't in Chicago now??" This is definitely English that gets said in America, but it's strongly associated with southerners and speakers of the "urban" dialect. It's pretty hard to list all these intricacies in each definition of slang! 

Honestly, when I teach my conversation partners slang, especially something that might be a little stronger like "fucked up" or "tickets to the gun show" (LOL, yes, I've taught this), I try to get them to wait and hear how it's used instead of just barging into their next conversation and going, "That's FUCKED UP," to their little old lady neighbor or somebody.

 What strategies do you have for learning and using slang, etc. in another language? Do you wait to hear it and get a feeling, or do you just find it online and immediately start trying it out? Let me know in the comments!