This volume explores theoretical approaches to the study of the Celtic Englishes including the so-called 'layer-cake-model' (substratum theory), 'half-eaten-triflemodel' of blurred dialect boundaries, prototype theory, corpus studies and quantification as well as sociolinguistic networks. The Englishes analysed represent all major Celtic varieties from Australia to America. The volume consists of 20 original contributions and attests both to their great sociocultural similarities and systems-linguistic differences.