In Chapter 5, the competing grammars model of morphosyntactic variation is introduced from both a sociolinguistic and computational perspective. The example of nominative substitution in Faroese is used to demonstrate the advantages of the model, in particular the combination of classic Optimality Theory constraints with a probabilistic activation hypothesis. The Faroese dative-subject verbs discussed in Chapters 2 and 4 occur in both dative–accusative and nominative–accusative case frames. The competing grammars model is outlined as a cogent explanation of the co-existence of both forms in use by a given speaker, sometimes within the same text or short series of utterances. Relevant factors proposed to influence selection of the nominative versus dative variants are discussed, including both grammatical and social/contextual variables. The importance of social meaning in determining case selection is highlighted, which presents a Rational Speech Act model of this morphosyntactic variable. In a section co-authored with Rob Mina, the issue of bimodally distributed judgement data is explored, in particular whether such data are effectively random or represent distinguishable dialects, and how to tell. Finally, neural approaches are discussed as an alternative model of competing grammars.

The introduction presents a general discussion of syntactic theories, contrasting transformational approaches with those that adopt feature-structural representations to show how they provide differing cognitive models of the human language faculty. The three key components of the OLG framework – Linking Theory (LT), Optimality Theory (OT) and Competing Grammars (CG) – are briefly laid out. These are motivated by phenomena that necessitate multiple levels of case, linking between levels that permits mismatches in some grammars, a means of restricting the linking apparatus while still capturing the data, and a cogent account of morphosyntactic variation. One such phenomenon is introduced: case-marking facts in Insular Scandinavian. The dative–nominative Icelandic predicates are contrasted with the Faroese dative–accusative pattern, along with plural number agreement with the object in Icelandic versus non-agreement in Faroese. Next, an overview is presented of the motivation for each theoretical component of OLG, in turn outlining the advantages of LT, OT and the CG hypothesis. The introduction concludes with an outline of the specific empirical findings from surveys conducted on the Faroe Islands and Iceland, including quirky case predicates and passives, followed by an overview of the book’s structure.

Chapter 3 outlines OLG’s core components, giving the prerequisite theoretical background for understanding the data analyses that follow. The Linking Theory section answers questions regarding levels of lexical–semantic and syntactic representation, mapping between levels, and the architecture of grammar. A short review is presented of the core propositions of Optimality Theory (OT) approaches to syntax, including a list of proposed constraints governing case-assignment. Linking Theory originates in Kiparsky (1997); the central innovation is that three levels of case – abstract, morphosyntactic and morphological – are distinguished, and the same set of binary features is seen to operate at all levels, though with level-appropriate realisation. The introduction to OT focuses on its application to the syntactic module of grammar; a key point is that a huge number of unlikely candidates are harmonically bounded by undominated or high-ranked constraints. Such markedness constraints interact with faithfulness constraints enforcing realisation of all features present in the input, preventing omission of input material other than in highly marked forms. This allows us to capture long-standing generalisations about phrase structure without having to claim they will be completely unviolated across languages: language-specific rankings may result in more or less marked structures.

Chapter 6 presents new data on Faroese personal and impersonal passives, in addition to a discussion of case preservation and availability of passive with the dative-subject verbs. First, data from further Faroese surveys are investigated. The analysis demonstrates that the proposed constraints regulating the passive, here simply the addition of PARSE, covers all relevant sentence types in both Faroese and Icelandic personal passives, and with DEP and ARGSP also the impersonal passives. The argumentation builds on Kiparsky (2013), providing additional empirical support for the Linking Theory approach. An important finding is that the facts of case substitution in the active and case non-preservation in the passive are related: it is argued that there are preserving versus non-preserving grammars, represented by the two competing rankings. Speakers have access to both rankings, and choice of verb strongly predicts which grammar is activated. This approach predicts patterns that emerge from the constraint rankings themselves. The non-preserving grammar (activated, for example, with uses of the verb ‘like’) implies availability of passive and nominative substitution, both of which hold true; likewise, the preserving grammar predicts unavailability of passive and case substitution, which again turn out to be true for the verb ‘need’.