L is convinced that the sole purpose of a sippy cup is to bang it against his highchair tray. He can't figure out how to drink from it for the life of him.
I gave up on the sippy cups. He likes a straw sippy better, but actually gets mad if I put liquid in it. He just wants to suck and chew on the chewy straw without getting anything to drink. I just gave him a cup instead. He took to it right away too!! I gave it to him at about 8 months(?). I put up video of him using his cup a while back.