The Polish Owczarek Nizinny, sometimes known as PONS, is a herding dog native to Poland. There it worked with larger more aggressive dogs to herd sheep. It was bred to be intelligent and fairly independent so as to make good decisions on how to help herd the livestock for them to avoid dangerous obstacles and continue towards their goal. It is a strong-willed dog, but it is also very affectionate and caring. This combination of temperament of independence and a desire to please can mean that your Polish Owczarek Nizinny appears trained one minute, and completely ignores its training the next.
It is helpful to socialize the dog early if you want it to obey your commands. The more it is socialized the more it will be willing to please the person it perceives as its master. This will help during obedience training to cement a better relationship. The obedience training should be done early so that the dog understands who is its master and what is expected of it. The dog is highly intelligent and needs a consistent and firm owner. If you give it mixed signals, it will simply decide it can make up its own mind. You must be consistent with your approach to boundaries and correct behavior so that the dog takes your lead. To keep from establishing poor habits due to improper training, just get the dog trained as early as possible.
The obedience training will help it to be an excellent watchdog too. It takes any job you give it quite seriously and is always willing to please and be counted as a valuable part of the family unit. There are Nizinnys who have taken their role as guards for children so seriously that they have given their lives to protect them when faced with an intruder or predatory animal. This is a dog that means business and is very loyal.
Some behavior that may be hard to keep the dog from doing is the nipping of people's heels. This is instinctive and comes from being used as a herd dog for many generations. The training may seem to be very well established, but the dog remains stubbornly independent. It doesn't take well to being offended and might act up if it thinks it has just cause. Don't leave the dog alone for too long as this breed gets bored and starts to act up when left alone. In some respects, if you don't train this dog early, it will attempt to train its owner to its preferences. It is just this strong-willed. To avoid this, get the dog obedience training as early as it is accepted into a program and work with it in a consistent and firm manner. This will ensure it gets the message that it is the dog and you are the owner.