Lalaa24

I have the cascade badge but whenever i try to use "cut" it says I still need a pokemon that has the ability. After I got the badge, Misty said that I can perform cut, is there something else i have to do? or how can I fix it? I have a similar problem with headbutt, I bought headbutt from the tutor in the Virvidian Maze and put it on my Sentret, but whenever I go up to the trees it still says I need a pokemon with headbutt?