Show the keyboard
Holding down the ctrl, option/alt, shift and command keys on their own or in combinations affects the character that is entered when the key is pressed. It is impossible to remember them all, so there is a handy keyboard display that can be shown. To resize this keyboard, position the mouse one pixel above the top edge and then click and drag it up or down. It can be made as big or small as you like.
1 Add menu tools
Go to System Preferences>keyboard and then select the ‘Keyboard’ tab. Tick the box next to ‘Show keyboard and emoji viewers in menu bar’ and click the icon to see them.
2 Check the keyboard
When you need to enter a character that is not on the keyboard, click the menu bar icon and select ‘Show Keyboard Viewer’ then press shift, ctrl, option or cmd to see the symbols.