Thrainish

At the start of the First Era, during the immigration of the western peoples to the continent of Thea who would establish themselves as the Empire of Thrain, the uniting, common language shared by them was Thrainish. While many races held on to the languages of their own lost homelands, namely the elves and dwarves, Thrainish became the backbone of the new nation.
The prominence of Thrainish lasted through the tenure of the Empire of Thrain, but has become transformed and adapted into the common tongue used by the modern nations. Currently, it is seen as a dead language, with some of the particulars of the syntax and phrasing being lost to time. Thrainish is only being kept relevant due to its use in old scholarly works necessitating at least a passable knowledge of the language for academics in historical fields.
One of the primary dialects that represents the bulk of historical writing that have survived into the modern era is High Thrainish. This 'court language' was typified by a highly complex sentence structures and a reliance on meanings within meanings, or masking the true intent of your words in subtext and figurative language. This complexity makes translations of some surviving works into common nearly impossible, and the true meaning of the text can only be appreciated with at least a moderate grasp of High Thrainish.
It is believed, though not confirmed, that the languages of the halflings and gnomes are descendant languages of a common dialect of High Thrainish from the island of Katiri. This Katiric Thrainish shares the both the meandering phrasing of Gnommish, as well as the Halfling propensity for overly specific naming conventions for machinery. As an example, in both Halfling and Katiric Thrainish, an oven roughly translates to 'box construction for the making hot of food'.