The Lithuanian language (or ietuvių kalba, pronounced [le’tu’vju ‘ka’ləba in Lithuanian] is considered as the most conservative living Indo-European language, retaining many features of the Proto-Indo-European language which are now almost entirely lost in other linguistic extensions of that group. Jonas Jablonskis (1860–1930) made significant contributions to the formation of the standard Lithuanian language, formulating its essential principles and contributing to its further development. Writing system: Latin (Lithuanian alphabet) Official language in: Lithuania, European Union