Germanic substrate hypothesis
The Germanic substrate hypothesis attempts to explain the purportedly distinctive nature of the Germanic languages within the context of the Indo-European languages. Based on the elements of Common Germanic vocabulary and syntax which do not seem to have cognates in other Indo-European languages, it claims that Proto-Germanic may have been either a creole or a contact language that subsumed a non-Indo-European substrate language, or a hybrid of two quite different Indo-European languages, mixing the centum and satem types. Which culture or cultures may have contributed the substrate material is an ongoing subject of academic debate and study. The non-Indo-European substrate hypothesis attempts to explain the anomalous features of Proto-Germanic as a result of creolization between an Indo-European and a non-Indo-European language. The non-Indo-European substrate theory was first proposed in 1910 by Sigmund Feist, who estimated that roughly a third of Proto-Germanic lexical items came from a non-Indo-European substrate and that the supposed reduction of the Proto-Germanic inflectional system was the result of pidginization with that substrate. Germanicist John A. Hawkins sets forth some modern arguments for a Germanic substrate. Hawkins argues that the Proto-Germans encountered a non-Indo-European speaking people and borrowed many features from their language. He hypothesizes that the first sound shift of Grimm's law was the result of non-native speakers attempting to pronounce Indo-European sounds and that they resorted to the closest sounds in their own language in their attempt to pronounce them. Kalevi Wiik, a phonologist, put forward a hypothesis that the pre-Germanic substrate was of a non-Indo-European Finnic origin. Wiik claimed that there are similarities between mistakes in English pronunciation typical of Finnish-speakers and the historical sound changes from Proto-Indo-European to Proto-Germanic. Wiik's argument is based on the assumption that only three language groups existed in pre-Indo-European Europe: Uralic, Indo-European and Basque, corresponding to three ice age refugia.