The process is the exactly same for older dogs as it is for puppies; prevent accidents from happening by using baby gates and a crate if possible, create a predictable schedule, learn to recognize your dog’s potty signals, accompany your dog outside and immediately reward for all outdoor elimination, properly clean any accidents and supervise your dog until you’re sure that he understands the rules.

Every dog needs to learn to walk on a leash. Besides the fact that most areas have leash laws, there will be times when keeping your dog on a leash is for his own safety. Learn how to introduce your dog or puppy to the leash, then teach him how to walk properly on the leash, even beside you on a bike. A loose leash walk teaches your dog not to pull or lunge when on ​the leash, making the experience more enjoyable for both you and your dog.
Dogs have become closely associated with humans through domestication and have also become sensitive to human communicative signals. Generally, they have a lot of exposure to human speech, especially during play, and are believed to have a good ability to recognize human speech. Two studies investigated the ability of a single dog that was believed to be exceptional in its understanding of language. Both studies revealed the potential for at least some dogs to develop an understanding of a large number of simple commands on the basis of just the sounds emitted by their owners. However the studies suggested that visual cues from the owner may be important for the understanding of more complex spoken commands.[81]
Konrad Most began training dogs for police work in Germany, and was appointed principal of the State Breeding and Training Establishment for police dogs in Berlin, where he carried out original research into training dogs for a broad range of service tasks. At the outbreak of war in 1914 he was charged with organising and directing the use of dogs to further the war effort. He headed the Experimental Institute for Armed Forces' Dogs during the Second World War, and afterwards ran the German Dog Farm, a centre for the training of working dogs, including assistance dogs for the blind. He played a leading role in the formation of the German Canine Research Society and Society for Animal Psychology.[10] His 1910 publication, Training Dogs: A Manual, emphasised using instinctive behavior such as the prey drive to train desired behaviors, advocated the use of compulsion and inducements, differentiated between primary and secondary reinforcers, and described shaping behaviors, chaining components of an activity, and the importance of timing rewards and punishments. The book demonstrated an understanding of the principles of operant conditioning almost thirty years before they were formally outlined by B.F. Skinner in The Behavior of Organisms.[11] While publishers of the 2001 reprint warn that some of the "compulsive inducements" such as the switch, the spiked collar and the forced compliance are unnecessarily harsh for today's pet dogs,[12] the basic principles of Most's methods are still used in police and military settings.[13]

If your dog isn’t giving you an obvious signal that they need to go out (like whining at the door) I suggest teaching them to ring a bell when they need to go outside. Some of the other signs dogs give that they need to go out such as pacing around or circling can be easy to miss if they’re in another room, which is why a noise based signal such as ringing a bell can make things easier.
One of the biggest predictors of a speedy potty training process is owner diligence. If you’re on top of your puppy’s schedule and you stick to a strict prevention and supervision regiment, you should be well on your way to potty training success within a few months. You can consider your puppy almost fully housetrained when you’ve gone an entire month without a single accident, but keep in mind that potty training is an inexact science. It’s best to have several dry months before you can really trust that your puppy understands the rules.
Animal behaviorists assert that using dominance to modify a behavior can suppress the behavior without addressing the underlying cause of the problem. It can exacerbate the problem and increase the dog's fear, anxiety, and aggression. Dogs that are subjected to repeated threats may react with aggression not because they are trying to be dominant, but because they feel threatened and afraid.[74]

A dog learns from interactions it has with its environment.[1] This can be through classical conditioning, where it forms an association between two stimuli; non-associative learning, where its behavior is modified through habituation or sensitisation; and operant conditioning, where it forms an association between an antecedent and its consequence.[2]