1. a car is behind you. It puts on it's signal to pass. You see that the oncoming car is too close. You
speed up slightly and move close to the passing
lane to warn the other car. You are practicing farfignugen, the car behind you and the oncoming car are experiencing farfignugen.
2. same scenario. You see the
road is clear ahead. You slow down slightly, and move toward the
edge of the road as an indicator that it is all clear ahead. You are practicing farfignugen; the car behind is experiencing farfignugen and practicing it if he takes your prompt.