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.
Russian language in Latvia
In 1989 Russian was the native language to 42% inhabitants, including 8% of population who were non-Russians, while 39% inhabitants spoke it fluently as a second language. From 1989 to 1990 an average of 47.5% pupils had enrolled in schools with Russian as the language of tuition, and the number was even higher (69.3%) in urban centers, suggesting that not only an overwhelming majority of non-Latvians, but also some Latvians had enrolled in Russian-language schools.