|Native speakers||3.2 million (2010)|
|Writing system||Latin (Lithuanian alphabet)|
|Official language in||Lithuania|
|Recognised minority language in||Poland|
|Regulated by||Commission of the Lithuanian Language|
Lithuanian (lietuvių kalba) is the official state language of Lithuania and is recognized as one of the official languages of the European Union. There are about 2.9 million native Lithuanian speakers in Lithuania and about 300,000 abroad. Lithuanian is a Baltic language, closely related to Latvian, although they are not mutually intelligible. It is written in a Latin alphabet. The Lithuanian language is believed to be the most conservative living Indo-European language, retaining many features of Proto-Indo-European now lost in other Indo-European languages.
Anyone wishing to hear how Indo-Europeans spoke should come and listen to a Lithuanian peasant.
Lithuanian still retains many of the original features of the nominal morphology found in some ancient Indo-European languages like Sanskrit and Latin, and has therefore been the focus of much study in the area of Indo-European linguistics. Studies in the field of comparative linguistics have shown it to be the most conservative living Indo-European language.
Lithuanian and other Baltic languages passed through a Proto-Balto-Slavic stage, from which Baltic languages retain numerous exclusive and non-exclusive lexical, morphological, phonological and accentual isoglosses in common with the Slavic languages, which represent their closest living Indo-European relatives. Moreover, with Lithuanian being so archaic in phonology, Slavic words can often be deduced from Lithuanian by regular sound laws.
According to some glottochronological speculations the Eastern Baltic languages split from the Western Baltic ones between AD 400 and AD 600. The Greek geographer Ptolemy had already written of two Baltic tribe/nations by name, the Galindai and Soudinoi (Γαλίνδαι, Σουδινοί) in the 2nd Century A.D. The differentiation between Lithuanian and Latvian started after AD 800; for a long period they could be considered dialects of a single language. At a minimum, transitional dialects existed until the 14th or 15th century, and perhaps as late as the 17th century. Also, the 13th- and 14th-century occupation of the western part of the Daugava basin (closely coinciding with the territory of modern Latvia) by the German Sword Brethren had a significant influence on the languages' independent development.
The earliest surviving written Lithuanian text is a translation dating from about 1503–1525 of the Lord's Prayer, the Hail Mary, and the Nicene Creed written in the Southern Aukštaitijan dialect. Printed books existed after 1547, but the level of literacy among Lithuanians was low through the 18th century and books were not commonly available. In 1864, following the January Uprising, Mikhail Muravyov, the Russian Governor General of Lithuania, banned the language in education and publishing, and barred use of the Latin alphabet altogether, although books printed in Lithuanian continued to be printed across the border in East Prussia and in the United States. Brought into the country by book smugglers despite the threat of stiff prison sentences, they helped fuel a growing nationalist sentiment that finally led to the lifting of the ban in 1904.
Jonas Jablonskis (1860–1930) made significant contributions to the formation of the standard Lithuanian language. The conventions of written Lithuanian had been evolving during the 19th century, but Jablonskis, in the introduction to his Lietuviškos kalbos gramatika, was the first to formulate and expound the essential principles that were so indispensable to its later development. His proposal for Standard Lithuanian was based on his native Western Aukštaitijan dialect with some features of the eastern Prussian Lithuanians' dialect spoken in Lithuania Minor . These dialects had preserved archaic phonetics mostly intact due to the influence of the neighbouring Old Prussian language, while the other dialects had experienced different phonetic shifts. However, the most archaic features are found in the South Aukštaitija dialect, such as: -tau, -tai usage instead of -čiau, -tum; in instead of į; and the endings -on, -un instead of -ą, -ų. Lithuanian has been the official language of Lithuania since 1918. During the Soviet occupation (see History of Lithuania), it was used in official discourse along with Russian which, as the official language of the USSR, took precedence over Lithuanian.
Lithuanian is one of two living Baltic languages, along with Latvian. An earlier Baltic language, Old Prussian, was extinct by the 19th century; the other Western Baltic languages, Curonian and Sudovian, went extinct earlier. Some theories, such as Jānis Endzelīns' considered that the Baltic languages form their own distinct branch of the family of Indo-European languages, but the most widely accepted opinion is the one that suggests the union of Baltic and Slavic languages into a distinct sub-family of Balto-Slavic languages amongst the Indo-European family of languages. Such opinion was first represented by the likes of August Schleicher, and to a certain extent, Antoine Meillet. Endzelīns thought that the similarity between Baltic and Slavic was explainable through language contact; Schleicher, Meillet and others on the other hand, gave arguments for a genetic kinship of the two families. An attempt to reconcile the opposed stances was made by Jan Michał Rozwadowski. He proposed that the two language groups were indeed a unity after the division of Indo-European, but also suggested that after the two had divided into separate entities (Baltic and Slavic), they had posterior contact. The genetic kinship view is augmented with the fact that Proto-Balto-Slavic is easily reconstructible with important proofs in historic prosody. The alleged (or certain, as certain as historic linguistics can be) contact similarities are seen in such phenomena as the existence of definite adjectives, which exist in both Baltic and Slavic and nowhere else in the Indo-European family (languages such as Albanian and the Scandinavian languages developed definite adjectives only in more recent times), that are not reconstructible for Proto-Balto-Slavic, meaning they are most likely to have had to have developed through language contact.
Vyacheslav Vsevolodovich Ivanov and Vladimir Toporov believed in the unity of Balto-Slavic, but not in the unity of Baltic. In the 1960s they proposed a new division, that into East-Baltic (Lithuanian and Latvian), West-Baltic (Old Prussian ) and Slavic. Ivanov-Toporov theory is gaining more and more weight in the community of scholars of comparative-historic grammar of Indo-European languages, and seems to be replacing the previous two stances in most P-I-E textbooks.