As I have said, during my various Montessori internships I literally followed Cheryl, Teri, Martha and Jerome around and wrote down the words that they used.
One example that stands out vividly: my five year old telling Martha that she wanted to hide all the color tablets around the classroom and have her (Martha) find them. She stated it, demanded it. I watched Martha, waiting for her to lose her temper, or threaten, like a normal person. Instead she calmly stated, twice: “I am not willing for you to do that.” She smiled pleasantly as she said it, as if she expected it to work. Then she said: “Let’s find something wonderful to do together.” And that was the end of that. Really.
Another incident also involved one of my children. Clara had apparently experimented with painting on the wall, instead of the paper on the easel nearby. When it was discovered, she was invited to wash the wall before she could go outside. (For insight on logical or natural consequences, check out Positive Discipline, which has criteria of related, respectful, reasonable, helpful. http://blog.positivediscipline.com/2013/05/logical-consequences.html)
Clara, oddly, did not enthusiastically applaud this notion. When she protested, argued, stomped her foot, and rolled on the floor, Teri calmly stated, from her position washing dishes : “You are not available to go outside.” And, a few times, sincerely, “I’m sorry. I hope you are ready soon.” There was no sarcasm involved, no passive aggressive eye rolls. After a period of time, Clara washed the wall and went outside. She was even proud of the job she’d done. Amazing.
Going back to the “3 Rs plus 1 H” above, children pick up on your tone, so trying to use these words in a snarky way will not have the same result. If it feels like punishment, that is, unrelated, (“Since you painted on the wall, you can’t watch “Barbie Gets Her Black Belt.”) disrespectful, (“That’s what you get for painting on the wall when I told you not to.”), unreasonable (“You cannot go outside for the rest of the week!”) or unhelpful (“I just can’t trust you!”) the result, even if the wall gets clean, will be a sneakier, resentful child.
As Ron Weasley said when his mother said “I’d better not catch you doing that again!”: “You won’t.”
Remember, changing behavior is one goal, maintaining the relationship is another.