This dissertation addresses the question of what the function of morphological case is in Icelandic. The working hypotheses of this book is that morphological case is a multifunctional category. Firstly, new verbs in Icelandic were collected and examined to cast light on the productivity of the morphological cases, revealing that not only are the nominative and accusative productive in Icelandic but also the dative. Secondly, a text-based investigation was conducted to find out what the statistical correlation is between morphological case, syntactic functions and thematic roles. Thus, a well-stratified corpus was compiled, containing Modern Icelandic texts from five written genres and one spoken genre. The study showed that there is a correlation between morphological case and both syntactic and semantic factors. Thirdly, a similar corpus was compiled for Old
Icelandic, containing four genres which are closest in content to the
Modern Icelandic genres. Some frequency differences were found between the two corpora, reflecting a change in the use of morphological case from Old to Modern Icelandic. Fourthly, a comparison of the development of case in English, Swedish and German revealed that the internal order of the changes within the case system is the same for the Germanic languages considered, with English leading the development, followed closely by Swedish, then German, and Icelandic lagging behind. The theoretical approach adopted in this work is that of Construction Grammar and the Usage-based model. The book also provides a critical view of the generative distinction between structural and lexical/idiosyncratic case.