copying and pasting

Is it just the keyboard shortcuts that do not work or copy paste in general?

What does not work? Not at all or the object is not pasted correctly?

There are other apps interfering with both modifier keys (which are needed for shortcuts) as with the clipboard.

@Gianluca24673914vqtj it works for me. Did it work in the past and suddenly it didn't? Was there a recent update?

1. I would strongly suggest, to reset your preferences first. Keyboard shortcut, Command K (Mac) or Control K (PC). And see if that clears that up. 
   
   
2. If that didn't work, I would suggest restarting your computer. After the computer restarted, and launch illustrator try again
   
   
3.  Look at the Keyboard Shortcuts. I am on a Mac, so mine is under Edit - Keyboard Shortcuts
   
   

   Go to Menu Commands - Edit - And look at the Copy and Paste keyboard shortcut (again, mine is in Mac)

   

   
   
   If you notice (in my set, I have 'place' because I created and overwritten the place command in Illsutrator to match what InDesign uses). If your copy and paste as a different keyboard and it isn't Control C and Control V, you can change it here. And give the new commands a new set name