"What command do I use to get him/her to ________________?"
Trainers get asked this a lot. As if there is one word that we can use to communicate to the dog exactly what we want.
If it were that simple, I could just charge $50 per word and produce a perfectly behaved dog in 15 minutes. I wouldn't even have to apparate to the owner's house to do it!
Here's the thing, dogs don't understand English...or any other language. Stay, Bleib, Reste, Zustan, and Blijf (Stay in German, French, Czech, and Dutch) all have the same meaning to dog....absolutely nothing until they form an association to the learned behavior.
I could just as easily use Eep, Opp, Ork, Ah-ah (for those who remember the Jetsons) in place of Sit, Down, Come, and Stay and it wouldn't matter to the dog as long as the association was made to the behavior.
The reason dogs learn words like "Go for a walk" so quickly is because those words consistently predict what's going to happen next. You probably don't ask your dog, "Wanna go for a walk?" and then put on your pajamas and climb into bed. There are plenty of words dogs pick up on when living with us, but if we want to get reliable behavior on cue, we need to be thoughtful about when and how we use those cues.
When choosing a cue, pick something that you will remember and feels natural. It's not going to help you - or your dog - if you choose the cue "Wait," but you have a tendency to say "Stay."
I don't care if you say "Heel" or "With me." Neither does your dog. What matters is what you reinforce. If you add your cues wisely, your dog will learn that cue + behavior = reinforcer.
In other words, when I hear _____ and I do _____, I get YUM.
Remember, positive reinforcement can work against you just as quickly as it can work for you. For example, if you say "Heel" but then follow your dog as he pulls you down the sidewalk, your dog may learn that "Heel" means "drag this slow and lazy human down the street."
On the other hand, if you don't say anything at all, but start by providing a steady stream of reinforcement for walking at your pace, and keeping the leash loose, and stop or back up when your dog starts to pull, your dog is going to learn that walking with you is more effective than pulling.
It's not about what you say, it's about what you reinforce.