The chapter explains the basic principles of linguistic change from a sociolinguistic variationist perspective. It begins with an explanation of the inextricable relationship between linguistic variation and change, and proceeds to demonstrate how language change can be observed, investigated, and explained. Sociolinguists can document and analyse language change using either the real-time method or the apparent-time construct; these methods and their advantages and pitfalls are explained and exemplified.

>What is “experimental syntax”? One could reasonably argue that all syntax is experimental, in the sense that traditional syntactic research is based on series of small, informal experiments. On the other hand, one might understand “experimental syntax” to refer to psycholinguistic and neurolinguistic experiments that focus on the structure of sentences. In practice, though, the term “experimental syntax” is generally used to refer to the intersection of these two approaches: studies that focus on the varying acceptability of sentence types and explore this by means of formal experiments. The goal of the handbook is to review what we have learned in the area of experimental syntax, but also to make sense of what this new body of knowledge is telling us, understand how experimental studies relate to the study of syntax more broadly, and explore what type of work we should be doing as the field moves forward.