Umm... I use both shifts. But I mainly use left shift. I only use right shift if I need to use a question mark and I'm holding my baby sister. Cause I always hold her in my left arm.
Right, most predominantly. I've trained myself over the years to hold the Shift button down with my pinkie and use the rest of the fingers on my right hand to press the desired button. If they can't extend all the way (the farthest I can go without messing up or having to redo is to the T key) then I use my left hand instead for anything beyond that. Besides, Caps Lock is above the left Shift button on my computer, so that throws me off when I try to use it. ._.