Abstract
<jats:p>Language isolates have long presented puzzles to historical linguists. With no identifiable sister‐languages, isolates are effectively single‐language linguistic lineages; however, probably all isolates have in fact had relatives in the past – whether they represent the last surviving member of a family that has otherwise disappeared, or they diverged from a known language family long ago. Isolates thus challenge the limits of existing historical methodologies to reliably demonstrate their relationships to other languages, and the many spurious attempts to classify them underscore the dangers of overreaching our methodological capacities. Nevertheless, we have many possibilities to explore the history of isolates, via internal reconstruction, dialect comparison, philological work with older attestations, and the identification of contact‐driven change. The resulting reconstructions can in turn feed comparative research that, in some cases, may shed new light on ancient relationships between a putative isolate and other attested language families. Isolates also offer significant challenges to our understanding of global patterns of language change and distribution: They make up more than a third of the world's genealogical linguistic lineages, despite representing less than 2 percent of the total number of languages; yet they are unevenly distributed around the world. Moreover, they appear to represent relatively extreme examples of both language maintenance and resistance to divergence over time, processes which must themselves make reference at least in part to sociocultural factors. This chapter deals with the phenomenon of language isolates, the challenges they present to efforts to establish language relationships, and their relevance for the study of language history, change, and maintenance.</jats:p>