Q: 3 Key

You will have to go to system preferences and follow the instructions on this link.  http://www.cnet.com/how-to/how-to-change-the-keyboard-language-in-os-x/

cjnali wrote:

 

hi. my 3 key used to have the pound sign in shift but now  since upgrading to el capitan it has this #.  how can I change it back please?

Go to system preferences/keyboard/input sources and make sure only British is on the list.  In particular remove US or ABC if they are there.