listentomystory is right Ansem Rin says it in the shop in the high road between Luca and mushroom rock. I can tell you part of the story. After killing the chocobo eating monster (and I mean killing it or pushing it over the cliff not letting it do it to you.) Go in to the shop and Rin does indeed say thank you in Albhed but when Tidus goes "Huh?" Rin apologises and says thankyou in English he then gives the primers and the excuse of having just gone back to the Albhed home to get supplies.
so listentomystory your turn