Internal Reconstruction

Internal Reconstruction is a historical linguistic method that reconstructs earlier stages of a single language by identifying internal inconsistencies, morphological irregularities, and distributional patterns within the language itself. Unlike the Comparative Method, which relies on comparing related languages, Internal Reconstruction uses evidence from within one language—such as suppletive forms, analogy-induced irregularities, and phonological asymmetries—to infer its historical structure and sound changes. This method is particularly valuable when only one written form of a language survives or when related languages are unavailable.