Are you bored with your dog who knows only three commands? Don't fret, my friend! You could probably use a little jazz.  Specific command words are not that difficult and important. The thing here should be the consistency of its usage. My friend, Wiki, here can give you a bit of a blast. Some of these certain commands are accepted as standard, while others are commonly used. 

To quote the rock band Chicago, they say it's a hard habit to break.  Perpetually stereotyping employment, marriage, and singularity: Age is but a hindrance but not for long. With approximately 15 minutes of training daily for 2 weeks straight, according to The Animal Planet, even the most stubborn dogs will give in.  These enduring canines will sit, roll over, and do whatever your heart desires. All you need is a strong sense of consistency, and a mouthful of patience under your sleeve.

In order to make this a quick fix, the trainers (or owners) should develop a positive attitude.  To feel frustrated and angry will not help at all. As a matter of fact, pets somehow feel how their owners experience; and that would not speed up the progress for even a bit.  As for the owner's side, unreasonable expectations should not be made for their pets. Unlike children sent to school for a 12-year formal education to get the basics, it is quite irrational to invest an uptight 12-week course for your dog to acquire the desired behavior, and earn the respect and discipline needed. Remember: all relationships require a bit of work.