We were gifted a Bradford Pear tree years ago. It has not done well and has many "trees" coming from the root, so I am not sure what type fruit this is. I is about the size of a cherry pit.
I must admit it did have me singing, "A partridge in a Pear Tree"!
According to Google they can cross pollinate with other pears and bear fruit. I have to say, although once I looked forward to seeing their blooms in the spring, I am no longer enamored by Bradford Pears.