The problem of late development of speech activity in young children without pronounced mental pathology is becoming more and more relevant every year (Borovtsova L.A. et al., 2015 Vatoropina S.V. et al. 2015). As a rule, all children after three years of age, whose speech is characterized by extremely limited use of linguistic means, are diagnosed with general speech underdevelopment (according to P.E. Levina). At the same time, the mechanisms of this disorder may be different. Insufficient knowledge of the clinical forms of speech underdevelopment, as well as the similarity of their manifestations, makes it difficult to differentiate the tempo delay of speech development and its impaired variant. Speech therapy intervention in these cases is often built without taking into account the clinical uniqueness of children and the mechanisms of delay in speech development, which, accordingly, reduces the effectiveness of the work carried out. At the same time, any phenomenon subjected to scientific analysis must be determined by its most characteristic features, distinguishing it from other similar phenomena. (Guseva A.Yu. 2022)