Parallel to Tolkien's professional work as a philologist, and sometimes overshadowing this work, to the effect that his academic output remained rather thin, was his affection for constructing languages. The most developed of these are Quenya and Sindarin, the etymological connection between which formed the core of much of Tolkien's "legendarium". Language and grammar for Tolkien was a matter of aesthetics and euphony, and Quenya in particular was designed from "phonaesthetic" considerations; it was intended as an "Elven-latin", and was phonologically based on Latin, with ingredients from Finnish, Welsh, English, and Greek. A notable addition came in late 1945 with Adûnaic or Númenórean, a language of a "faintly Semitic flavour", connected with Tolkien's Atlantis legend, which by "The Notion Club Papers" ties directly into his ideas about the inability of language to be inherited, and via the "Second Age" and the story of Eärendil was grounded in the "legendarium", thereby providing a link of Tolkien's 20th-century "real primary world" with the legendary past of his Middle-earth.