He is not for sure what you want him to do. When training you must make each command repitious. Keep working with him on that one command again and again. It could take hours, days or weeks depending on the breed of dog that you are working with. Work him on that one command until he will do it each and every time then move on to a new command. Work him on that command until he has it down then work him on his first command then his second and continue this pattern. But repetition is the key.