어디서나, 어디서든지 is same..(anywhere) but 어디든지 is different..(to anywhere) I can go to anywhere. (어디(로)든지 갈 수 있다.) You can buy it anywhere. (어디서든지or 어디서나 살수 있다.) ============================ I have a question.. I eat pizza everyday.. Is this mean you eat the pizza every single day? Becuase I thought "피자를 언제 어디서든 먹는다' should be "I eat the pizza anytime, anywhere" since everyday is '매일', everywhere is '모든 곳'

우리는 매일 피자를 먹어요. .어디서나 I think the meaning is same, however this is more natural.

I wish i could help you but i know nothing about the Korean language. good luck