The article is dedicated to the 100th anniversary of the outstanding Russian linguist, professor of Saratov State University Olga B. Sirotinina (born in 1923). The article presents and analyzes a number of scientific ideas of the scholar: the necessity to work out new approaches to syntactic units; the interaction of primary (factual) and secondary (organizational) levels of communication; attention of the author to the addressee as a leading principle of linguistic ecology; semantic diffusion as a dynamic process in the Russian discourse. In the late 20th century Olga B. Sirotinina in her research of the colloquial speech determined new approaches to communicative units: alongside the syntax of predicative units she developed the syntax of non-predicative ones. Her works prove that while studying real discourse a special focus should be put on the role of functional words as the effectiveness of communication is directly determined by the interaction of factual and organizational communication units. The author’s concern about the addressee is one of the main principles of linguistic ecology. It is the author who is primarily responsible for the success of communication, so they are supposed to make a number of reasonable efforts to facilitate for the addressee the perception of their message. The process of semantic diffusion is often connected nowadays with the violation of linguo-ecological principles. This problem is one of the main concerns of Olga B. Sirotinina: de to weakened and broadened meaning some words start to mean almost anything, are used widely and turn into fashionable words. Excessive use of diffused lexis leads to the language system impoverishment as well as to numerous social and professional risks. The ideas of Olga B. Sirotinina under discussion have organized the research of real communication units and determined the directions of the development of Saratov linguistic school in the late 20th – early 21st centuries. The article focuses on the tendencies in the development of these ideas by Saratov linguists.