Language proficiency is one of key competences of an individual nowadays. The authors highlight two systems used for description of language proficiency in Russia. One of them is subjective assessment that assumes such categories as «I can read and translate with a dictionary», «I can speak», «I can speak English fluently». The other assessment is objective assessment as it refers to the Common European Framework of Reference for Languages. The article contains a comparative-historical analysis of the notion «language proficiency» formation to fully understand the factors influencing the formation of a contemporary subjective language proficiency assessment. Based on the background reading analysis, four periods of formation the «language proficiency» notion are coined, with reference to the foreign language function in various ages: communicative- applied, academic/enlightening, ideology-populist and integrative. Foreign language competence requirements are reflected in categories factors influencing the formation of a contemporary subjective language proficiency assessment.