give one cause of the introduction of many non-indo-european words into english
The Germanic substrate hypothesis is an attempt to explain the distinctive nature of the Germanic languages within the context of the Indo-European languages. It claims that the elements of the Common Germanic vocabulary and syntactical forms, which do not seem to have cognates in other Indo-European languages, suggest 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, from the centum and satem types, respectively.