How do I make comments visible in Microsoft Word 2011 for OS X?
Right now, you are seeing comments in the sidebar because of a change that you made at some point in "Preferences." This should be what you are currently seeing:



What you are hoping to get back to, if I understand correctly, is this:



To make this change, go to the menu bar at the top of the screen and click on "Word" which will invoke a drop down menu. From the menu, select "Preferences..." Once the preferences window opens, select "Track Changes." When the Track Changes pane opens, make sure to check the radio box at the bottom that reads "Use balloons to display changes" (see screenshot below). This will make the change you're looking for.