Daniel Klein (grammarian)
Daniel Klein (Lithuanian: Danielius Kleinas) (1609–1666) was a Lutheran pastor and scholar from Tilsit, Duchy of Prussia, who is best known for writing the first grammar book of the Lithuanian language.
In 1653 Klein published the first grammar book of the Lithuanian language (Grammatica Litvanica), written in Latin. Klein coined the distinctive Lithuanian letter Ė. He also wrote a Lithuanian dictionary, but it was left unpublished.
Klein published collections of Lithuanian hymns (Lit. giesmes), some of which he wrote himself.