He also researched Lithuanian anthroponymy, word formation, phonology and morphology.
[5] From 1941 to 1943, Klimas did Lithuanian studies and philosophy at Vytautas Magnus University.
In 1944, as the Red Army troops began re-occupying Lithuania, he fled the country.
In 1948, he resettled in the United States and continued his studies at the University of Pennsylvania, Philadelphia, in Alfred Senn's class up until 1950.
From 1957 to 1989, he worked in the University of Rochester, New York, where he taught Germanic studies, Indo-European, Baltic, and Slavic linguistics.