ABSTRACT
Approximately half of the language families indigenous to North America North of Mexico have been identified as isolates, families consisting of a single language. The figure is necessarily approximate for several reasons. The first is the quality of data. Some languages are represented by so little documentation, often of poor quality, that demonstrating genetic relationships to any other languages with confidence is difficult. A second is the continuum between dialects and languages. A third is the potentially deep impact of language contact. Ultimately, isolate status does not entail particular structural characteristics inherent in the language itself: it is more about their potential relatives.
