jess0811
I love those sippy cups, they don't leak like the nubys (or if your son is like mine, he shortly discovered that all he had to do was hold the nuby upside down and put a little pressure on the spout and behold, everything came out!) Anyway, I think they're a little harder to suck from and he just has to get the hang of it. If he's thirsty enough, he'll work at it :)

Kim P
My daughter had a hard time with them at first, but she's gotten the hang of them. It just will take some getting used to. I tried the Nuby's too and she found her other one the other day, and she got too much in her mouth and it ran all the way down the front of her. Keep trying.