Latvian language
The Middle dialect is spoken in central and Southwestern Latvia. Kursenieki language, which used to be spoken along Curonian Spit, is closely related to the varieties of middle dialect spoken in Courland. The dialect is divided into the Vidzeme variety, the Curonian variety and the Semigallian variety. The Vidzeme variety and the Semigallian variety are closer to each other than to the Curonian variety, which is more archaic than the other two. There are three intonations in the Middle dialect. In the Semigallian variety, "ŗ" is still used. Standard Latvian is based on the middle dialect.
Lithuanian language
Lithuanian is one of two living Baltic languages, along with Latvian. An earlier Baltic language, Old Prussian, was extinct by the 18th century; the other Western Baltic languages, Curonian and Sudovian, became extinct earlier. Some theories, such as that of 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 an 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 explicable through language contact while Schleicher, Meillet and others argued for a genetic kinship between the two families.