The message in the navel: (ir)realis and negation in Swahili

It is argued that the encoding of conceptual categories such as ‘realis’ should be investigated by analyzing the meanings of linguistic signs rather than by focusing on a priori message-categories that may not be expressed by specific linguistic forms. Applying this method to the expression of ‘realis’ in Swahili reveals a complex relationship between tense-aspect-modality, negation, and realis status in which some forms signal information related to irrealis, but no forms explicitly signal the meaning ‘realis’; the two negation markers span the realis/irrealis divide. Sign-based analysis makes it possible to identify subtle differences between apparently synonymous messages that are conveyed by forms differing in realis status.

► Realis is investigated via meanings of linguistic signs, not as an a priori category.
► Swahili tense-aspect-modality markers signal irrealis but not realis status.
► Swahili negation markers signal degree of forcefulness of assertion, not irrealis.
► Argument supported by discourse and quantitative data.