The article deals with language features of A. Denisov’s biographical essay ‘Mynam plenys’ pegdzeme’ (‘How I escaped from captivity’). In the year of its publication (1919) the standards of the Udmurt had not yet been published, therefore there is no uniformity in the writing of the particles and unions, the components of compound words in some cases are written separately, in other - in one word. Most of the other spelling deviations from the literary norms receive a satisfactory explanation with regard to the phonetic and partly morphological features of native (southern) dialect of the author: the presence of the phoneme y, occurring in the vicinity of the palatal consonants, palatalization of dental n in the position after i, formation of accusative plural nouns and personal pronouns using formant -yz, use of nouns and postpositions in Elative with an indicator -is' and others. The text is rich in lexical dialecticisms typical of the southern dialects of the Udmurt language.