Productivity of argument structure constructions is a new emerging field within cognitive-functional linguistics. The term productivity as used in linguistic research contains at least three subconcepts: ‘extensibility’, ‘regularity’, and ‘generality’. The focus in this study of case and argument structure constructions in Icelandic is on the concept of extensibility, while generality and regularity are regarded as derivative of extensibility. Productivity is considered to be a function of type frequency, semantic coherence, and the inverse correlation between these two. This study establishes productivity as an emergent feature of the grammatical system, in an analysis that is grounded in a usage-based constructional approach, where constructions are organized into lexicality-schematicity hierarchies. The view of syntactic productivity advocated here offers a unified account of productivity, in that it captures different degrees of productivity, ranging from highly productive patterns through various intermediate degrees of productivity to low-level analogical extensions.

Pulling together the threads of forty years of research on oblique subjects in the Germanic languages, this book introduces a novel approach to grammatical relations, based on a definition of subject as the first argument of the argument structure. New data are presented from Gothic, Old Saxon, Old Norse-Icelandic, Old Swedish and Old Danish, as well as from Icelandic, Faroese and German. This includes alternating Dat-Nom/Nom-Dat predicates, where either argument, the dative or the nominative, takes on subject behavior. The subject concept is modeled with the formalism of Construction Grammar, both synchronically and for the purpose of reconstructing grammatical relations for Proto-Germanic.

The present chapter gives an overview of valency classes in Icelandic and the most common, noticeable, or productive alternations found in the language. The over-view is based on my own native-speaker knowledge of the language, on my earlier research and on the existing literature on Icelandic. Most of the examples are at-tested, taken from real texts found online, supplemented with some constructed examples. The chapter is structured as follows: Section 2 presents the basics of Icelandic by placing it into its genealogical, linguistic and social context. Section 3 deals with basic valency, focusing particularly on two- and three-place predicates in Icelandic. There I present an overview of which predicates may instantiate the different argument structure constructions: Nominative Subject Construction, Accusative Subject Construction, Dative Subject Construction, and the different sub-constructions of ditransitives. Section 4 deals with uncoded alternations, i.e. alternations not coded on the verb. These are divided into three types, case variations, case and structure changing alternations, and structure changing alternations. Section 5 deals with coded alternations, i.e. alternations that are coded on the verb, such as the Active-Passive Alternation, the Impersonal Passive, the Transitive-Inchoative, the Reflexive and the Mediopassive. In Section 6, additional alternations are discussed, namely the Oblique Ambitransitive, which is found with accusative, dative and genitive subjects, and the Actional Passive, which is an extension of the Impersonal Passive, found with transitive and ditransitive predicates. Section 7 concludes the present discussion on alternations and valency classes in Icelandic.