Microsoft Word does not respond to keyboard shortcuts
Check in the edit menu and see what MS Word thinks its shortcut keys are for cut, copy, and paste. 

If they're not the keys you’re expecting, maybe something was accidentally configured in Word’s preferences, e.g. some alternate key mapping.  

Also, verify that there are not alternative key mappings specified in the Mac System Preferences, both system wide and application specific, that may be modifying your shortcut mappings to other keys.