this is really good! you seem to have a good understanding of planes, values and shapes of them. The thing I notice that could use some tweaking is the shadow could be in perspective more. rotated -45 degrees perhaps? notice the negative space.. examine the top left point of the pear (reference photo) and visualize a line from that point to the top of the shadow. in the reference that almost looks like a 90 degree angle, while in your study it seems a 45 degree. All that being said i think you're well on your way :)