After meeting Paarthurnax and doing stuff as the legendary dragonborn, you got tired and wanted to just have somewhere to Relax. That is when you were going to the Throat of the World, the highest peak in Skyrim, knowing your good old Dragon friend Paarthurnax is there, and that he feels lonely cause he doesn't have someone to talk to up there

Paarthurnax: ah Dovahkiin! Nice to see you again! Zu'u los naak, hi los hi dii fent kos bonaar hi los tiid wah zok daar. Hi los fahdon hi!

Paarthurnax: I'm sure there must be a reason you came to me isn't there?

You told him that you wanted to relax and have missed him

Paarthurnax: haha. Thank you Dovahkiin! How about we kill time while we are here together? No one can bother us! So? What do you say?

Paarthurnax: I can teach you how to speak in my tounge fluently! Like you grew up with Dovahzul being your born language! What do you say? Just ask me what you want to know!