The Lithuanian language has two dialects (tarmės): Aukštaičių (Aukštaitian, Highland Lithuanian), Žemaičių/Žemaitiu (Samogitian, Lowland Lithuanian). There are significant differences between standard Lithuanian and Samogitian. The modern Samogitian dialect formed in the 13th-16th centuries under the influence of the Curonian language. Lithuanian dialects are closely connected with ethnographical regions of Lithuania.
Dialects are divided into subdialects (patarmės). Both dialects have 3 subdialects. Samogitian is divided into West, North and South; Aukštaitian into West (Soduviečiai), Dainavian and East (the South and East dialects are also known as Dzūkian dialects due to their frequent use of dz for standard dž). Each subdialect is divided into smaller units – speeches (šnektos).
Standard Lithuanian is derived mostly from Western Aukštaitian dialects, including the Eastern dialect of Lithuania Minor. Influence of other dialects is more significant in the vocabulary of standard Lithuanian.