I was traning my Staraptor then when he was supposed to learn the move Final Gambit he didn't what's wrong?
What game is it? If its not black or white he dosen't learn it because it didn't exist. If it is black and white, either level him up or go to the move relearned and learn t with a heart scale. Since your tag says platinum he CAN'T learn it. It can only be learned in black or white.