I mostly fall asleep on my stomach, but I sleep on my sides as well. I can't even remotely get close to sleep if I'm laying on my back.
I'm most comfortable on my stomach, with my head turned to one side so I can breath. Sometimes I move onto one side, sometimes I hold onto a pillow, but I'm practically never on my back and prefer my stomach.
Depends. I try and avoid sleeping on my back, since I have a higher chance of getting sleep paralysis. I tend to lie on my right side, though recently I've been sleeping on my front, probably due to the heat or something.
sometimes i cant sleep on my back
Mainly on my sides, but occasionally on my back.
I sleep both on my side and back. Curling up on my side is more comfortable but sleeping on my back prevents me from drooling for the most part.