Hi, After several months of thinking, I finally switched to Mac by buying a white MacBook yesterday. I'm trying to master the shortcuts since I use them all the time but I'm having troubles using the shortcut for looking up a word in the dictionary (Command-control-D). I tried to use it many times but it didn't work, I don't know if I'm supposed to fix something in the system preferences? I mean, it's really boring that I have to right-click words to perform this task !! Another question is what is the Fn button used for ? it shows me my desktop whenever I push it, but I'm sure there's something more about it lol any suggestions ?