Chapter 2 presents the research on parameters within GB Theory. After classifying the parameters from Rizzi’s (2014) list into five different types, the chapter reviews the null subject parameter (Rizzi 1978), the parameterization of Subjacency (Rizzi 1978), and the parameter of S′-deletion (Chomsky 1981a). Some influential proposals which were originally formulated as non-parametric systematic differences are then reviewed, namely Huang’s (1982) insights on the locus of wh-movement, Kayne’s (1983) treatment of preposition stranding and epistemic verbs, and den Besten’s (1983) account of V2. The next section discusses Hale’s (1983) parameterization of the Projection Principle, Baker’s (1988) analysis of incorporation processes, Pollock’s (1989) split INFL hypothesis, and lastly, Koopman and Sportiche’s (1991) proposed cross-linguistic difference in nominative Case assignment. The chapter ends by covering some influential proposals concerning language acquisition, that is, Hyams’s (1986) hypothesis that parameters have preset default values, Manzini and Wexler’s (1987) parameterized notion of governing category, and finally, the latter’s link to the Subset Principle.

Chapter 3 focuses on the debate about the concept of parameter which took place during the first decade of the twenty-first century. The first two positions discussed are Kayne’s (2000, 2005) microparametric approach and Baker’s (2001, 2008) macroparametric approach. These two approaches are then confronted with Newmeyer’s (2004, 2005) criticism. Finally, two lines of linguistic inquiry which are particularly relevant to the evaluation of the notion of parameter are presented, namely Roberts and Holmberg’s (2010) hierarchical parametric model and Longobardi’s and his collaborators’ Parametric Comparison Method (PCM). On the one hand, Roberts and Holmberg’s (2010) model overcomes the limitations of micro- and macroparameters by combining a lexically based, microparametric view of linguistic variation with the idea that parametric variation is an emergent property of the interaction of Universal Grammar, primary linguistic data, and third factor considerations. On the other hand, the unprecedented results achieved by the PCM in establishing the genealogical relations among languages on the basis of syntactic comparison arguably attest to the validity of the parametric model.

Chapter 4 aims at evaluating the classical parameters of GB Theory from today’s point of view. The first parameters discussed are those concerning S′-deletion, Subjacency, long distance anaphora, the Projection Principle, and nominative Case assignment, which are shown either to refer to obsolete theoretical concepts or to be reducible to other, more basic theories. Then, the discussion turns to those parameters whose epistemological status is still being upheld in Minimalism, that is, those concerning null subject, V-to-T and V-to-C movement, polysynthesis, and overt vs. covert wh-movement, by looking at their respective minimalist reformulations. What emerges from this investigation is that, strikingly, the only traditional parameters here reviewed which still enjoy an independent theoretical status are those which in Chapter 2 have been labeled as Spellout parameters. Moreover, the overt vs. covert wh-movement parameter could well be an exception in this sense. In fact, assuming Richards N. (2010) or an equivalent PF-based account is on the right track, wh-movement pertains to the A-P interface.

The book concludes with a brief discussion of a number of the themes covered in the book, in particular, multilingualism. The chapter points out that linguistic contact is likely to be more central to the processes of language change than has been assumed by many specialists.

This chapter introduces readers to the processes underlying language ontact and how these relate to both personal and group multilingualism. Concepts such as superstratal, adstratal and substratal directions of contact are considered, as are the levels of influence put forward by Thomason and the integration process put forward by Winford. Interpretations of borrowing and interference are aired. A case study of Estonian Halbdeutsch is used to exemplify and test many of these ideas.

The central idea of this chapter is koineisation, the process by which discrete varieties tend to form into a new compromise variety when speakers of these varieties find themelves living side by side. Dialect levelling and new dialect formation are central forces in the process. The case study considers what happens when closely related but discrete language varieties come together in new circumstances. Primary focus is given to contact between Scandinavian varieties and Low German in the late medieval and early modern periods and between Old English and Viking Norse in northern England in the early medieval period.

This chapter considers semi-creoles, varieties which share features with creoles (and pidgins) but appear to be more like ‘mainstream’ varieties of the lexifier language than either of these states. The view is taken that all of these states and their backgrounds can be seen more as being points on a large-scale continuum. The case study considers potential histories for African American Vernacular English.

This chapter considers what effects language death (otherwise, language shift) might have upon language change, both in the language which is losing speakers and in those which are gaining them. Theory is tested against experience. The largely psycholinguistic concept of language attrition is introduced as a means of demonstrating how individual speakers might ‘lose’ their language over time. Potential differences in terms of survival and effect between immigrant and autochthonous languages are discussed. Effects of dominant language on dominated, and vice versa, are also analysed. The case study, on Shetland Norn, illustrates a number of the issues considered.