can you change the layout of the keys on the iMac keyboard

Hi, Gary.

Thank you for visiting Apple Support Communities.

I understand you want to change the keyboard layout on your iMac. I would need the specific layout that you are looking for to provide a better answer. However, here are a couple resources that will give you an idea on how to change your keyboard layout.

OS X El Capitan: Use Dvorak keyboard layouts

OS X El Capitan: Use the Keyboard Viewer

OS X El Capitan: Use global keyboard shortcuts

Cheers