1 Introduction

This section introduces the research background concerning the part-of-speech transition of adverbs with the prefix na- in modern Russian. It points out the close connections between adverbs and other word classes, with adverbs often serving as intermediaries in part-of-speech transitions. Since the 21st century, Russian scholars have explored the conversion phenomena between adverbs and other word classes, yet research on adverbs with the prefix na- performing multiple part-of-speech functions in specific contexts remains limited. Through consulting two authoritative dictionaries, discrepancies were found in the definitions of the part-of-speech properties of such adverbs, and not all their functional roles were clearly indicated, posing challenges for Russian language learning and teaching. The section reviews the research trajectory of Russian academia on the phenomenon of "one word, multiple parts of speech" since the 1950s, highlighting Babaitseva’s transition theory, including the concepts of diachronic transition and synchronic transition, as well as the notion of functional homonyms. This study aims to analyze and discuss the transitional characteristics and their causes of adverbs with the prefix na- based on the transition theory.

2 Part-of-Speech Characteristics and Classification of Russian Adverbs with the Prefix na-

This section delves into the part-of-speech characteristics and classification of Russian adverbs with the prefix na-. Regarding part-of-speech characteristics, these adverbs semantically modify the degree, direction, time, and manner of actions, and syntactically function as adverbials dependent on various word classes, even serving as non-agreeing attributes or modifying entire sentences. Some adverbs with the prefix na- also exhibit features of state words, enabling the evaluation of the state of people or objects in the environment and functioning as main components in impersonal sentences. Furthermore, their meanings and usages are close to prepositions, allowing them to denote relationships between things and endow nouns with specific meanings. Morphologically, they share similar word-formation patterns with non-primary simple prepositions. These adverbs can also serve as function words like coordinating conjunctions or negative particles, and in specific contexts, express modal meanings, thus becoming modal words.

In terms of classification, since adverbs with the prefix na- are pronounced identically in different contexts but belong to different grammatical categories and serve distinct syntactic roles, they are categorized as functional homonyms. Based on their word class origins and conversion outcomes, these adverbs are divided into two major categories: substantive word class homonym communities and mixed-type homonym communities. Substantive word class homonym communities include the "adverb–state word" subclass, while mixed-type homonym communities encompass subclasses such as "adverb–preposition," "adverb–conjunction," "adverb–modal word," and "adverb–multiclass hybrid," with the "adverb–preposition" homonym community being the largest in number.

3 Transitional Characteristics of Russian Adverbs with the Prefix na- as Functional Homonyms

This section discusses how Russian adverbs with the prefix na- can exhibit the semantic features, grammatical categories, and valency capacities of other word classes such as prepositions, state words, and modal words in specific contexts, forming hybrid word characteristics and demonstrating incomplete part-of-speech transitions at the synchronic level. Taking naprotiv as an example, the transitional features are explained using the transition scale model. In the transition from adverb to modal word, different stages of naprotiv display distinct characteristics: at stage A, naprotiv functions as an adverb modifying verbs, serving as a locative adverbial; at stage Ab, it begins to also function as a preposition, governing nouns in oblique cases; at stage AB, through the fixed expression naprotiv togo, it becomes a compound conjunction with contrastive and adversative meanings while expressing modal evaluative meanings; at stage aB, naprotiv resembles an auxiliary word, commenting on communicative content and imparting emotional tones, transitioning toward a modal word; and at stage B, it fully converts into a modal word, used solely as an interjection to express the speaker's evaluative attitude.

4 Causes of the Transitional Characteristics of Russian Adverbs with the Prefix na-

This section thoroughly explores the causes behind the transitional characteristics of Russian adverbs with the prefix na-, identifying grammaticalization, degrammaticalization, and lexicalization within the language system as key factors. Grammaticalization causes content words to gradually lose their lexical meanings, while degrammaticalization allows grammatical elements to gain autonomy or substantiality at multiple levels. Taking naprotiv as an example, it underwent bidirectional evolution involving both degrammaticalization and grammaticalization, whereas navernoe primarily experienced unidirectional grammaticalization. Lexicalization refers to the process whereby certain linguistic units transform into independent content words, as seen with navalom, which evolved from the instrumental case form of a noun to an adverb and then acquired the categorical meaning and syntactic functions of a state word. The occurrence of these processes is closely related to the principle of linguistic economy, enabling adverbs with the prefix na- to perform multiple roles, economize linguistic means, and convey rich information.

5 Conclusion

This section concludes that Russian adverbs with the prefix na- can achieve part-of-speech conversion in different contexts, forming functional homonymy. Through transition theory, the dynamic changes in semantic and grammatical roles of the case study naprotiv and its conversion mechanisms were analyzed. It points out that their transitional characteristics are driven by factors such as grammaticalization, with the principle of linguistic economy and expressive needs also playing a role. This research provides a new perspective for determining the part-of-speech attribution of such adverbs, aiding in understanding the complex relationships and regularities among linguistic phenomena. In teaching, this approach can be used to cultivate students' autonomous inquiry abilities, enhancing their contextual awareness and application of linguistic knowledge.