I am playing Skyrim on Xbox360. I have found to additional words in the game aside from the one you start with. I have since killed 2 dragons and when I try to learn the word by using the Dragon soul it keeps telling me. "you must have a dragon soul to learn this". Glitch or do I need to have more dragon souls?
Just click 'X' when you have the word highlighted under 'Souls' in the menu that you want to learn. If you have unused Dragon souls you will learn it.