Sippy cup help??


How do I teach my baby to use sippy cups? I have 2 different kinds, the straw one he seems to have grasped but he prefers to just chew the straw. The other one he can't figure out and gets so frustrated he just throws it. Honestly was kinda hoping daycare would help him out but so far nothing and he's starting to refuse formula. He wants real food. Any advice?