How do words change inflection class? Diachronic evidence from Norwegian

In cases of diachronic change, do lexemes shift inflection class gradually or in one leap? Evidence is presented from Norwegian verbs and nouns. These seem to behave somewhat differently: Verbs shift more gradually, nouns more abruptly. An alternative account for the verbs, presented by Kusters [Kusters, W., 2003. Linguistic Complexity: The Influence of Social Change (LOT 77). LOT, Leiden], arguing that verbs shift class in one leap, is argued to be inadequate. The difference between verbs and nouns in Norwegian is unexpected, given Rhodes’s [Rhodes, R., 1987. Paradigms large and small. In: Aske, J. (Ed.), Proceedings of the Thirteenth Annual Meeting of the Berkeley Linguistics society, vol. 13, pp. 223–234] claim that noun inflection is more ‘quirky’ than is verb inflection. Perhaps the difference has to do with the observation that, in Norwegian, the “basic form” of the verb is more inflectionally informative than that of the noun. It is shown that the diachronic changes in Norwegian do not endanger the No Blur Principle [Carstairs-McCarthy, A., 1994. Inflection class, gender and the principle of contrast. Language 70, 737–788].