For the first time , scientifically Baltic languages were researched .
For the first time , scientifically Baltic languages were compared with other Indo - European languages in the 19th century , when Franz Bopp in 1816 laid the ground for comparative linguistics .
For the first time , scientifically Baltic languages were researched and compared with other Indo - European languages in the 19th century , when Franz Bopp in 1816 laid the ground for comparative linguistics .