Morphologically Ambiguous Adverbs and Prepositions: Theoretical and Practical Issues of Distinction

Abstract

This article explores one of the challenging issues in the automatic morphological analysis of the Lithuanian language: the morphological ambiguity between adverbs and prepositions. This phenomenon frequently complicates the work of automatic morphological taggers, as a single word can often be classified as different parts of speech or interpreted as various inflectional forms of the same word, leading to the selection of incorrect grammatical tags from several possible options. The aim of the study is to clarify how the distinction between adverbs and prepositions is reflected in Lithuanian grammars, dictionaries, and text corpora, and to provide recommendations for ambiguous cases.
By reviewing Lithuanian dictionaries and grammars, problematic cases were identified where the distinction between adverbs and prepositions is unclear even in theory. This theoretical ambiguity further complicates the differentiation of coinciding adverbs and prepositions in practical applications. The article reveals both theoretical and practical challenges related to distinguishing between adverbs and prepositions and discusses possibilities for creating clearer rules to address this issue. The research specifically focuses on ten Lithuanian words that can function either as adverbs or prepositions: arčiau, arčiausiai, arti, iki, netoli, paraleliai, piečiau, skersai, šiauriau, už. The study examines how these words are represented in dictionaries and grammars, as well as the differences in usage frequency and contextual properties within text corpora.

The findings indicate that the boundaries between adverbs and prepositions are often blurred. Dictionaries and grammars vary in their definitions and categorizations of these words, which contributes to the inconsistency in morphological tagging.
Finally, the article proposes suggestions for grammatical rules to improve the accuracy of automatic recognition of adverbs and prepositions in Lithuanian. These improvements are particularly relevant for the ongoing development of Lithuanian digital language resources and tools.
Overall, this work contributes to better understanding and resolving the morphological ambiguity between adverbs and prepositions in Lithuanian, paving the way for more effective computational linguistic solutions in the future.