How to fix UnboundLocalError

[wavic]

Using global variables is not recommended.
You can do the same by passing answers_right as an argument to the function.

def finder(bone_name, correct):
    if bone_name.lower() in foot_bones:
        print("correct!")
        correct += 1
    else:
        print("incorrect")

Then call the function.

bone_name = input("enter name of a bone: ")
finder(bone_name, answers_right)
print(answers_right)