I already speak a fair bit of Russian.
In a classroom where I often study, I once wrote «покой» on the blackboard. When I came back on another day, someone had completed what I had written on the board with «нам только снится» :) ^^ And I wanted to write «really?», but in Russian, obviously. But I don’t know what word I should choose exactly in this context!
I can't seem to understand what word I should use to translate «really?» (as a reaction to something someone just said): правда? действительно? or even another word? I remember a friend of mine using «вообще» in this case, but when I try to translate it, I get quite a different meaning from what I'm looking for. What would a native say? (Please warn me if you suggest slang words! ;) :) )