In this chapter, the remit of theoretical linguistics is located within the background of a set of theoretical questions. These questions pertain to issues of ontology, methodology, acquisition, communication, and evolution. The overarching field is distinguished from other pursuits within applied linguistics that have a more practical focus but are argued to subsume certain experimental approaches. The first part of the chapter discusses the role of grammaticality and formal grammars in linguistic theory. Here, the issue of whether the rules of language have normative force is introduced as well as whether the target of scientific linguistics is individual languages or some universal core of human language generally. The question of what a grammar is, a theory, model, or some other device, is presented based on a brief literature review on the topic with a nudge towards a certain scientific instrumentalism about these matters. Next, the chapter asks whether linguistics is best viewed as an empirical social or cognitive science. Arguments are presented on both sides. Naturalism and normativity figure prominently in this debate. Finally, an outline of each chapter of the book is provided with an aim to either precisify or reflect on the philosophical issues presented in this opening chapter.

In this chapter, we address the issues related to sentence grammaticality and acceptability. We begin with a discussion of the relationship between the two notions, and point out that despite the differences in theoretical conceptualization, the two notions, grammaticality and acceptability, are often confluent and that grammaticality is usually measured as acceptability in linguistic research. We then discuss factors beyond syntax that may influence sentence acceptability, including processing factors and semantic/pragmatic considerations. Finally, we discuss the measurement of acceptability, via either experimental methods or corpus-based analyses. To conclude, we show in this chapter how grammaticality, a seemingly purely syntactic notion, is often materialized as acceptability, which encompasses multiple linguistic modules that go beyond syntax.

Acceptability and grammaticality are clearly closely related, but the relationship is not always straightforward. Sometimes, sentences that are thought to be ungrammatical are perceived as acceptable, leading to an illusion of grammaticality, or grammatical sentences are perceived as unacceptable, leading to an illusion of ungrammaticality. Such cases occur with morphological ambiguity, attachment ambiguity, agreement attraction, and negative polarity items, among others. Processing difficulty is one of the factors that can lower the acceptability of a grammatical sentence, as may be seen in the effects of constituent length and dependency length on acceptability. In some cases, such as superiority violations and island violations, it has been argued that these may actually be grammatical, but unacceptable, though this is the topic of much ongoing research involving cross-linguistic work and studies on repeated exposure (satiation) and memory capacity. Having better models of acceptability and better ways of directly measuring grammaticality would be desirable.

Satiation refers to an increase, over time, in the willingness of a native-speaker consultant to agree that a given syntactic structure is grammatically well-formed. Studies show that satiation can be induced under laboratory conditions, within a single testing session; that the effect is restricted to a small number of sentence types (chiefly those involving wh-extraction from wh-islands, subjects, and certain complex NPs); that experimentally induced satiation can persist for at least four weeks; and that satiation sometimes ”carries over” to syntactically related sentence types. Tables are provided showing the methods and findings of satiation studies on seven different types of syntactic violation. Larger issues include (i) whether the satiable sentence types form a natural class within generative syntax; (ii) whether satiation is a unitary phenomenon, or merely a family of similar phenomena; and (iii) how, in principle, satiation can serve as a tool for language research.