Vietnamese sentence-final modal particles (SFMPs) have long posed a theoretical challenge in linguistics due to their context-dependent meanings and interaction-sensitive functions. This lack of ontological clarity has directly affected contrastiv...
Vietnamese sentence-final modal particles (SFMPs) have long posed a theoretical challenge in linguistics due to their context-dependent meanings and interaction-sensitive functions. This lack of ontological clarity has directly affected contrastive linguistics and translation studies, particularly in attempts to identify English equivalents for Vietnamese SFMPs. Specifically, the problem of equivalence cannot be resolved through lexical substitution alone, as English does not possess a morphologically equivalent closed class of SFMPs. Given that, this dissertation aims to investigate the ontological essence and English translation of Vietnamese SFMPs within an integrated semiotic framework. Grounded in relational realism and interpretivist epistemology, a qualitatively driven mixed-method design was implemented through two interrelated sub-studies. The first sub-study developed a semiotic redefinition of Vietnamese SFMPs. The study argues that Vietnamese SFMPs exhibit both arbitrary and non-arbitrary dimensions. This finding complicates the dichotomy between arbitrariness and iconicity and suggests that Vietnamese SFMPs operate within a layered semiotic system. The second sub-study addressed the question of their English equivalence. Rather than searching for direct lexical correspondences, the dissertation modelled equivalence as topological reconfiguration across semiotic spaces. Since English distributes interpersonal functions across intonation, modal verbs, discourse markers, and syntactic constructions, the translation of Vietnamese SFMPs requires reconstructing interpersonal force within the target cultural matrix. On that basis, translation was conceptualized as a process of interpretant translation in which the goal was not form replication but the stabilization of meaning under new constraints. The study also demonstrated that there was no stable isomorphic mapping between Vietnamese SFMPs and their English counterparts. SFMP meaning is therefore best understood as topologically relative and path-dependent, emerging through interactional negotiation rather than fixed correspondence. Therefore, this dissertation makes contributions not only in terms of professional expertise but also in practical aspects. Specifically, it not only serves as a theoretical bridge between semiotics, Vietnamese linguistics, and translation studies but also repositions SFMPs as semiotic operators, thereby providing a topologically structured understanding of equivalence. Furthermore, the study is expected to provide valuable support for bilingual speakers and translators in translation work in general, and for Vietnamese SFMPs into English in particular.