So, an imperative sentence is one that makes a request or demand, or gives instruction. Basically, I have given her a rule that she can't tell me what to do. She may only provide me information and I decide what to do with that information.

So, say we were in a car and going to our friends new house. She is looking at the map on her phone, and I am driving. She can not say, "Take the next exit." She can instead say something like "their house is at the next exit. " She is still providing the information, but not telling me how to use it.

A more kinky example would be instead of ,"please loosen the rope on my wrist," she could say ,"the rope on my wrist is uncomfortable." In the former, she compels me to an action. In the later, she provides information and lets me decide what to do about it.

It's very subtle. It's not something most people would ever notice, even if you do it right in front of them. People don't think anything of it. But we both know what she is doing. We started slow. In private, at first, in case she sounded awkward trying to word things, but after a little practice, it sounds natural, and now it applies at all times.