This article aims to expand the concept of fixedness in language from stable autonomous structures to socially shared patterns of communication. The study examined conversational utterances that sounded strange or ‘unnatural’ to members of a speech community and explored the reasons behind such intuitive perceptions. Some of these utterances contradicted the community members’ expectations based on sedimented patterns of linguistic resources of various sizes and associated conventional meanings beyond dictionary definitions (i.e. cognitive frame). Others challenged their expectations concerning positional fitness and socio-relational concerns (i.e. interactional frame). The observed expectations for sedimented patterns of communication likely result from a lifetime of experience talking and hearing about the world around them in ways that are accepted by other members of the speech community. The dynamic perspective on fixedness is particularly meaningful for context-dependent languages like Japanese that rely heavily on unexpressed shared knowledge in co-constructing meanings and actions.