Diftongeja

Diftongeja is a fictional term used in speculative linguistics and worldbuilding to describe a hypothetical sociolinguistic phenomenon. The concept is not attested in real-world linguistics and there is no empirical data supporting it as a natural language process. In many treatments, diftongeja serves as a thought experiment to explore how bilingual repertoires, diglossia, or language-contact dynamics might interact within a single utterance.

Definition and types: A diftongeja occurs when a speaker switches between two distinct linguistic systems within the same discourse, producing a dual-tongue effect. This can be manifested at different levels: phonological (sound inventories swap mid-sentence), morphosyntactic (grammatical patterns switch), or orthographic (writing conventions alternate). Usage may reflect social factors such as audience, identity, or topic, and can complicate mutual intelligibility.

Relation to other concepts and uses: Diftongeja is often discussed alongside code-switching, macaronic language, and diglossia, but it emphasizes the intra-sentence integration of dual repertoires rather than broader community-level language domains. In fiction and worldbuilding, it serves as a tool to explore multilingual identity, power relations, and cognitive aspects of language contact.