Zoeb tu ne sembles pas avoir compris la question de Nicole. ^^ Ben and bon do not mean the same thing at all, they're not interchangeable. Ben is an interjection when you explain something, also written as bah, beh and sometimes bin (I do not recommend the last one though, I think it's pretty ugly lol). Examples of usage: Ben... c'est lui qui est venu me parler. / Well... he started talking to me. Ben non c'est pas moi. / Well no it's not me. Ben oui. / Of course. I don't know why it seems kinda awkward to put "well" at every sentence in English, but in French it's totally natural. Bon is a less formal version of "bien" which marks sufficiency, I hope following examples will help you fathom the idea: Bon, j'en ai marre. Bon, on y va ? (When you're tired of waiting for someone you have to go out with) There's also a combination of both interjections "bon bah" that is used when you have no other option. Bon bah on ira sans lui. / It seems like we'll have to go without him.

Yes :) It is actually slang. like ouais as you said; which would be more of an american (Yas!) there's also things like je le kiffe (je l'aime). it's just slang my dear :)