Struggling to fill the months until “Game of Thrones” stabs its way back onto our screens? Then why not use your time learning to speak the language of the Dothraki, the nomadic warriors featured on the hit show. Game of Thrones, the enormously popular HBO TV show adapted from a series of books, spins an epic yarn of kings and commoners, as disparate forces across a fantasy realm vie for control of the Iron Throne. One people less concerned with world domination however are the Dothraki, the famed horse riders who roam the Dothraki Sea (actually a broad stretch of grassland) in tribes called Khalasars, raiding, enslaving and speaking in a coarse, guttural tongue.