what might otherwise be a comitative form for an instrumental and vice versa, where the forms appear to be instrumental ("by means of the ... men", "by means of the ... rains"), despite being comitative ("accompanying the ... man", "accompanying the ... rains"). Finally, word-final -m is decreasingly common in High Valyrian. Contracted inflections that end in -m will often assimilate to -n unless the next word begins with a vowel or a labial consonant. Class I adjectives decline differently for each of the four noun classes. Adjective classes II and III both conflate rather more forms, failing to distinguish between solar and lunar nouns and failing to distinguish between terrestrial and aquatic nouns. Duolingo course On October 31, 2016, a course in High Valyrian for English speakers began to be constructed in the Duolingo Language Incubator. David J. Peterson is one of the contributors to the course. The beta version was released on July 12, 2017. In April 2019, the course was updated in anticipation of Game of Thrones' eighth and final season. As a part of this update, Peterson created audio for the course's lessons and exercises. Bastard Valyrian In the world of the novel and TV series, the Nine Free Cities of Essos speak locally evolved variants of Valyrian known as Bastard Valyrian, described by the character Tyrion in A Dance with Dragons as "not so much a dialect as nine dialects on the way to becoming separate tongues". Peterson described the relationship between High Valyrian and Bastard Valyrian as being similar to that between Classical Latin and the Romance languages evolved from Vulgar Latin, or more accurately between Classical Arabic and the modern varieties of Arabic, in that High Valyrian is intelligible, with some difficulty, to a speaker of a local Essoan language. Slaver's Bay dialects The slave cities of Slaver's Bay are lands of the ancient Ghiscari Empire that was conquered and annexed by Valyria, so they speak related languages descended from High Valyrian with the substrate of the local Ghiscari languages. Peterson noted that with regard to the vocabulary of the derived languages, "If it’s got a 'j' in an odd place, it’s probably Ghiscari in origin." Astapori Valyrian The first derivative Valyrian language to be featured in the series was Astapori Valyrian, a variety from the city of Astapor in Slaver's Bay. It appeared in the third-season premiere episode "Valar Dohaeris". Peterson created