Rotating things horizontally?

[Mikeinhistory]

So, how do I get an object standing vertical to rotate horizontally? I have tried pressing X twice, and this works on some objects, but not with others. If I attempt to select a wooden post for example it has 4 blue squares under it and X does not allow for that kind of rotation. I can remove it from building, but I cannot rotate it still. What am I missing? Thank you.

 

[Abletudu]

When an item has the blue squares under it, it signifies that it is on the grid and the "X" key would have no effect. Items without the blue squares can be manipulated with the "X" key.