I have white spots on my tongue and they hurt. What could they be?

Ok so i am 14 years old and i have been getting white spots on my tongue. They hurt when i try eating something crunchy. I have had my tonsils and abnoids out if that may help. I know they are not canker sores because i have had cankers before, I started having them on the tip of my tongue and now there in the middle. So if anyone has any answers i am very greatful. Thank you