What to talk about with a guy dat likes me?

So i talk to a guy since 6 months ago. He likes me alot , like i almost think its an obssesion even doe he says it isint :D well he always seems to find wat to talk about on da fone but i dont : X im a shy girl, 17 . Hes 19 ughh please help me . Hes dominican also im from Uruguay (: thanks