Shortcut for euro symbol on macbook air comes up as TM

Option Key & 2 [no need to use shift]

on UK keyboard it's just alt 2

If you use US layout, the combination for € sign should be Option+Shift+2, while Option+2 gives ™.

If you have more than one keyboard layout, you can click on the flag at the menu bar and choose Show Keyboard Viewer. It will show you the hidden symbols on the keys when you press modifier keys.

Hi,

Hold down the shift and option keys and press the number 2 key.