The implicative structure of Asama verb paradigms

Formal and computational linguistics can enhance descriptive linguistics of endangered languages by providing them with precise models and quantitative perspectives. We exemplify the benefits of such an approach with the case of Asama’s verb inflectional morphology. We show that a Word-and-Paradigm framework can provide interesting insights and allow for both the identification and the quantification of the sources of uncertainty in the implicative relations within Asama’s verb paradigms. We describe Asama’s verb morphology by considering whole forms rather than exponents only, and we factor its alternation patterns in two types: segmental alternations and suprasegmental alternations. Measures of Shannon’s conditional entropy are then used to estimate the respective contributions of these factors to the complexity of the system. Suprasegmental alternations turn out to be the major source of uncertainty in implicative relations, and vowel length and tone alternations cannot be treated separately but strongly interact. We also show how the principal parts of the inflectional system can be determined with conditional entropy measures of n -ary implicative relations.