First and foremost, dog training is language training.

You aren't really teaching them to do things, you're teaching them to understand the sounds and movements you make when you want them to do things.

This means that regardless of anything else, you have to be consistent in both the execution of and understanding of what language you're using.

Example: you say sit when training with a calm voice and a little lilt at the end. But in daily life, you say sit sharply and without the hand gesture you'd been using during lessons. When that's the case, you can't blame the dog for not understanding automatically that you want them to do the thing you used different words for.

Animals don't process language the same way we do, but we can still run into problems understanding what someone else wants us to do when they say it in an unusual way. Why would a dog magically understand the difference between "sit, puppy", "puppy, sit", and/or "dammit, why won't you sit?!"

Consistency is how we learn languages as humans, and we have sections of our brain dedicated to language that are very developed compared to even our closest relatives in the animal kingdom.

The flip side of that is that you have to train yourself at the same time as the dog. You have to train yourself in the commands you want them to connect with a behavior. Make sure you learn how you're saying things, and any secondary or tertiary signals are included.

Example: if you want the dog to eventually know that the word sit, a hand gesture, and a tone of voice mean you want them to sit, you have to consistently use those commands. Eventually, even the dumbest dog will figure out that any of those commands mean you want their butt on the floor, but if you aren't consistent with them, it'll take longer.

Remember, that dog hears your words and tone, sees your movements and posture, and reads your facial expressions. *All" of those are part of the command you're teaching them to respond to with a specific behavior.

That's why a lot of trainers have a process of introducing those things in a controlled and specific way.

And, if you deviate from the command you actually taught (like screaming word sit while making angry face, bent over and shaking a finger at them instead of the usual), don't be mad at them for not responding to this totally new and different signal grouping with a behavior you taught them with a different combination of signals.