How do i make a grindstone in minecraft properly?

the slab caught me too. what it's actually for: put an enchanted item in and it strips every enchant except curses and gives you some xp back. two of the same damaged tool in it combines them, but the result comes out unenchanted, so use an anvil for those.

Top row: stick, stone slab, stick. Middle row: planks, empty, planks. Bottom row empty. The slab trips people up, it has to be a stone slab, not a wooden one, and not a full stone block either.