Latvian language
Upper Latvian dialect is spoken in Eastern Latvia. It is set apart from rest of the Latvian by number of phonetic differences. The dialect has two main varieties – Selonian and Non-Selonian. There is a standard language, the Latgalian language, which is based on deep Non-Selonian varieties spoken in south of Latgale. The term "Latgalian" is sometimes also applied to all Non-Selonian varieties or even the whole dialect. However, it is unclear if it is accurate to use the term for any varieties besides the standard language. While the term may refer to varieties spoken in Latgale or by Latgalians, not all speakers identify as speaking Latgalian, for example, speakers of deep Non-Selonian varieties in Vidzeme explicitly deny speaking Latgalian.
Pitch-accent language
Two languages of the Baltic branch of the Indo-European family survive today, namely Lithuanian and Latvian. (Another Baltic language, Old Prussian, died out in the 18th century.) Both languages have a tonal accent that is believed to derive from the ancestral Proto-Indo-European language.
Baltic tones are often classified as either "acute" or "circumflex." However, these labels indicate a diachronic correspondence rather than a phonetic one. For example, the "acute" accent is falling in Lithuanian but a high level tone in Latvian and is presumed to have been rising in Old Prussian and Classical Greek. The "circumflex" is rising in Lithuanian but falling in Latvian, Prussian and Classical Greek.