This article provides a description of the compatibility features of the verb ‘начати’ in the Old Russian language. The material for this study was electronic transcriptions of the most ancient Russian Chronicles, published on the portal “Manuscript: Slavic Written Heritage”. Within the framework of this work, a quantitative-statistical research method was used, which allows not only to determine the number of occurrences of a particular language unit, but also to statistically substantiate the combinatorial nature of the components with each other. To obtain statistical data on the compatibility of the verb ‘начати, the module of n-grams of the IAS “Manuscript” was used, which makes it possible to identify text combinations with a different number of components and analyze the frequency of functioning of language units in texts. As part of this work, we used the T-score measure, which allows us to determine the most frequent combinations, as well as to identify how non-random the strength of the connection between words in a phrase is. The analysis of statistical data confirms the effectiveness of the use of association measures when working with the Old Russian text. It was revealed that the verb ‘начати’ is most often combined with the infinitive of imperfective verbs. The dictionaries used in the work demonstrate a fairly wide semantics for the verb ‘начати’. In the chronicle text, we recorded the functioning of this unit in only two meanings.