Thank you for your question.  This spring has been challenging for most fruit trees, in terms of weather and the abundance of fungal diseases that thrive in cool, moist environments.  Add to that a great diminution of pollinators, and you see these results.  Without photos of the tree and closeup ones of the leaves, we can't give you specifics about the cause(s).  If your tree is a sweet cherry variety, it must have a different variety of sweet cherry close enough for cross-pollination.  If you can provide more information, we can try to be more specific.  Good luck!

Thanks, but do you have any photos of a leaf that appears infected (holes, discoloration, etc.) that is not dead?  We're in need of information like fungal spores, color and size of the holes, or photos of insects.  It appears that you have "bumps" along the central rib, but I can't tell whether it is the top or underside of the leaf, or see them clearly enough to ID them.  Where on the tree are the dying leaves occurring?  Can't tell from the picture.

Is your tree a sweet or sour cherry?  There are 47 diseases, and 26 insect species--not to mention the weather and environment--that can cause problems.  So we need a lot of accurate information to diagnose a problem.