Thread: "You can't teach an old dog new tricks"

Dont get into reprimand but rather thinking of enforcing. If he doesnt respond immediately you enforce it. The means of doing so depends on the dog and command eg if a dog doesnt stop when told while coming towards you an aggressive step forward can stop them. Try going to short distance come commands when you say come.run away and get him to chase you. Build the distance from there. Get excited with it and make yourself more interesting him getting to you and getting a rub etc is the reward.
This is one idea that may/may not work depending on the relationship you have. Best would be to have someone in the know see how you and dog interract amd go from.there