spirantization, gemination, and prenasalization: For example, the absolutive suffix -pi appears in different forms, according to the noun stem to which it is suffixed: movi-ppi 'nose' sappI-vi 'belly' -mpi 'tongue' See also Lenition Fortition Consonant gradation Rendaku Sonority hierarchy Apophony Elision Historical linguistics References Further reading Grijzenhout, Janet. 2011. 'Consonant Mutation' in Marc van Oostendorp, Colin J. Ewen, Elizabeth Hume and Keren Rice (eds.) The Blackwell Companion to Phonology (Oxford: Blackwell) III: 1537-1558. Zimmer, Stefan. The Celtic Mutations: some typological comparisons. A Companion in Linguistics, a Festschrift for Anders Ahlqvist, ed. B. Smelik, R. Hofman, C. Hamans, D. Cram. Nijmegen: de Keltische Draak / Münster: Nodus 2004, 127-140. Celtic languages Linguistic morphology Phonology Syntax