J.F.
It is actually a good thing that he does not hold his own bottle. Why? He is not attached to it, and therefor, when the time comes to get rid of the bottles and have only a sippy cup, he will not have near the issues that some kids have. I would suggest giving him a sippy cup that has a straw to suck, he will not have to tilt it to get a drink (since he wont tilt a bottle to drink. It usually doesn't take long for a baby to get the hang of sucking thru a straw since they have sucked a bottle all their life. (My child was the same as yours and we had a very easy transition from bottle to straw sippy cup). I would stop trying to get him to hold his bottle. It is recommended to get rid of the bottles after they have their 1st birthday, so get him to the straw sippy cup. I hopes this helps.