First of all, Lithuanian is a very old language. It is related to Sanskrit (a classical language of India) Latin and Ancient Greek. It is the oldest surviving Indo-European language, which has preserved the most phonetical and morphological aspects of the proto-language which many other European languages come from. It is very important to the field of Indo-European language studies, which carries out research on the origin, development, similarities and differences of Indo-European languages. Scientists of different nationalities in this field use Lithuanian as their language of communication at their conferences! (Department of Lithuanian studies University of Vilnius)