I'm trying to reorder my multimonitor layout and I don't understand
the syntax error I am getting, xmonad,hs follows:
The problem is that the ++ to append the keys change is being applied to the wrong thing. I would add parentheses (open after `additionalKeys`, close after the list comprehension).
Also, next time please use a proper attachment --- I had to fix several line wraps in your pasted xmonad.hs, and am slightly surprised the indentation survived pasting.