My son is just not getting the hang of his sippy cup. He likes to chew on it , but when it comes to…

My son is just not getting the hang of his sippy cup. He likes to chew on it , but when it comes to getting water out its a struggle. if he does suck it is accidental and he won't do it again. He drinks from a water bottle fine (when I hold it for him) and will grab it for more when he's thirsty. I just wish he would get the hang of the sippy cup 😩

Any suggestions !?! (He is 7 months)