Original question: What slang words or phrases do you recommend using for non-English speakers among friends?
I think with this question, you mean “non-native English speakers”. Even if you did not mean this, this question is extremely difficult to answer. Anyone answering this question needs to know a lot more about the situation. How old are you? How old are your friends? Do they belong to a specific culture or sub-culture? Are they from/in a specific country?
The problem with slang is that it is extremely dependent on the answers to the aforementioned questions and it changes at the drop of a hat (meaning extremely quickly). If I were to say that something was “lit” or told my mother she was “woke”, she would (most likely) have no idea what I am talking about. My grandmother certainly would not. I sometimes “simp” for people on TikTok, but people who don’t use TikTok would have absolutely no idea what that means.
How would you respond to “old fruit”? Someone in the US might think you are being offensive and calling them gay but it is really a term of endearment in the UK to address a man (although it is dated). I honestly have no idea who other native speakers outside of these countries would react, so I definitely wouldn’t use it with anyone not from the UK (I don’t use it anyway, but it is a good example).
What about “faggot”? It is a pejorative term (slang) for a gay man but the short form “fag” can also refer to a cigarette and a faggot is also a type of meatball popular in Wales and the Midlands in the UK.
In summary, we need to know more information about you and your situation before we can a detailed and thorough answer to this question to satisfy your situation.