I come from an explosive background, multi-original to say the least and languages are part of the deal. I can dialogue in 4 idioms.
Some people, unlike myself, have constantly grown in a single milieu, speaking a dominant language. These people cultivate an authentic slang, unadultered by outside influences. I catch onto their language immediately and fondly listen to them.
In contrast, I am strongly bilingual: I shift from English to French in my thinking, writing and dreaming. I can also understand and discourse my mother and father tongues: Arabic and Farsi with ease. I frequently mingle with a variety of people who have the same linguistic melanges. My relatives and friends, for the most part, are not what I will call here, slang talkers.
French people can be categorized as slang talkers because they rarely speak another language and have very coercive methods of safeguarding their language from outside influences. I take great pleasure in conversing with my son's first grade teacher or our riding instructor. They use terminology and expressions that are rich and poetic and always very precise. The first grade teacher has a distinctive Marseillais accent full of the sunny mediterranean culture that it represents.
Iranians who live in Iran, who haven't been to Los Angeles or Dubai, have kept an Iranian slang whose intonation, accent and particular expressions always enchant me. The main pleasure I derive from watching the Iranian films, of which Separation won the Golden Globes, is to listen to them speak my mother tongue, in the purest form of idiomatic Farsi, with its fancy formalities and the innate sense of humor beneath it all.
Lebanese are a breed of their own. Their slang is made of a crazy mix of languages. Also their colloquial Arabic is "italianized"(ie made light) version of an otherwise rich and daunting classical Arabic. The only thing about me that isn't Lebanese is probably my ownership of their slang. I am familiar with it, have grown up understanding my paternal side and certainly appreciate the finesse of its significance and wry humor.
The only way I can pull it off, is by pretending to speak it. I sometimes tease friends and relatives with an attempted electronic message like the one below:
وينك ؟ مشغول؟ كتير جعباله شوفك. أنا كمان عندي ميت شغله بس ماشية حاله. شو بدك .... كتبله شي كلمه ورجاع على شعلك. شو لازمله أهوي!!!!!
My father only has one answer for this: "na'sik bbm bil arabi!" and his non pardoning: "ma asalik!" which translates into "all we needed was you to bbm in Arabic and .....the second term just doesn't have a translation!
Now that is slang for you!