In modern Russian, it is quite common for one linguistic unit –

a word, its form, or an entire construction – to be used in a role

characteristic of another. The transposition of parts of speech

involves not only semantic reinterpretation but also the

transformation of the grammatical properties of the original unit,

ultimately leading to its transition to another lexical-grammatical

class. The article examines one type of transposition – the process of

substantivization in Russian and Uzbek languages, particularly the

transition of both content words and function words into the category

of nouns. It has been established that in the languages being

compared, adjectives and participles are most actively substantivized,

while pronouns and numerals transition to the category of nouns

significantly less frequently. As a result of substantivization, words

change their semantic, morphological, and syntactic characteristics,

and also undergo functional transformations.

The article also examines the linguistic factors causing the

manifestations of substantivization and investigates the ways in

which words from different parts of speech are substantivized in

Russian and Uzbek. The phenomenon of substantivization can be

observed in all speech styles of the compared languages; therefore,

this study presents examples from literary works and newspaper

articles where substantivized words are widely used. The conducted

research is of interest to specialists working in the field of

comparative linguistics.