newbie prelude question

Hi, I was investigating the prelude the other day. I was bewildered with the highly complicated expressions, and interesting syntax. My question is : "are there any tweaks in the prelude?" I mean : are there any language constructs which have some sort of special treatment? Which ones are hard wired to the compiler? Am I free to use those special constructs defined in the prelude, in my own programs (other than the functions of course)? Thanks