K.S.
I didn't get a chance to read all the responses so I don't know if this was already suggested but what I did when I was teaching my little ones to use a sippy cup was remove the stopper in the lid for the first few week or so til they really got the hang of it. When they were able to get the water out with just a little effort, they learned how to use it, then I was able to put the stopper back in and it was a smooth transition. They couldn't even tell a difference. It'll be messy for a little while, but I found it was worth it to have something other than the bottle to use for meals and snacks. Good luck!