Describing languoids: When incommensurability meets the language-dialect continuum

Many linguists maintain that the grammars of different languages are incommensurable. This poses the problem of how to compare them. One proposed solution is to distinguish between descriptive categories for individual languages and comparative categories for crosslinguistic comparisons. At the same time, it is also commonly assumed that language-internal variation can be described in a unitary manner, thereby presupposing that different dialects of the same language are commensurable. However, it is well known that the language-dialect distinction is not categorical but rather forms a continuum. This raises the question: Where lies the boundary between commensurability and incommensurability? This question is best addressed in terms of the notion of languoid, a cover term that includes languages, smaller entities such as dialects and registers, but also larger assemblages such as genealogical and areal groupings. This article proposes replacing the notion of language-specific descriptive category with that of languoid-associated descriptive category. Since languoids can be of arbitrary size, such categories may form the basis for crosslinguistic comparisons, alongside comparative categories. What this means is that different languoids, regardless of how close or distant they are to each other, may be commensurable with respect to some linguistic features but incommensurable with regard to others.