Until the 20th century, the language's spoken form was the language of only the upper noble classes and urban population, as Russian peasants from the countryside continued to speak in their own dialects. By the mid-20th century, such dialects were forced out with the introduction of the compulsory education system that was established by the Soviet government. Despite the formalization of Standard Russian, some nonstandard dialectal features (such as fricative [ɣ] in Southern Russian dialects) are still observed in colloquial speech.