How to Add & Switch Languages in Mac OS X. If you are actually going to use the secondary language full time or you are aiming to improve your proficiency, learning the keystrokes to change the keyboard language can be very advantageous, and adding an

The panel has a list of all supported languages that you can type in on macOS. Scroll through the list or use the search bar to find the language you want to add. If you need to, you can also add a keyboard layout with it from the panel on the right. Sele

Usually this is because you're using a different keyboard map to the keys on the keyboard, i.e. a US-purchased Mac being used with a British English keyboard. Press alt-3 to get the other symbol above the number 3.