Natural linguistic processes in the vernacular layer throughout its development have noticeable features interesting for linguistic science. This article considers the state of Russian youth slang, used by 17-18-year-old teenagers, existing at present in the city of Kazan, and presents the most frequently encountered slang units, their definitions and origin, examples of their use, and the main trends in their functioning. We recorded the main features of this layer of the vernacular language, used by young people in everyday informal speech, often existing outside the norms of the literary language: a number of words gravitate towards the formation of lexical-semantic groups (school slang units, online slang units related to certain subcultures, etc.); slang has a tendency to become obsolete fairly quickly, moving into the passive vocabulary; modern slang is characterized by economy of linguistic means and laconicism; the international nature of slang as a product of adolescent interactions within online communities; the presence of synonymous series compared to obsolete slang vocabulary; the emergence of new slang as a result of filling lexical gaps in missing nominations; the narrowing and expansion of the English words semantics as a result of borrowings into the Russian social dialect; cultural diffusion, etc.