Forsyth is an expert in the Ogham script, and has provided readings for a number of Ogham inscriptions, including the Buckquoy spindle-whorl and the Lunnasting stone.[2] Forsyth has reinterpreted a number of Pictish Ogham stone inscriptions that were previously thought to be written in an unknown pre-Indo-European language, and has argued that the Picts spoke a Brythonic language.[3]
1995. "Language in Pictland: spoken and written". In Nicoll, E.H. and Forsyth, K. (eds.), A Pictish Panorama: the story of the Picts. Pinkfoot Press. ISBN1-874012-10-5
1995. "Some thoughts on Pictish symbols as a formal writing system". In Henderson, I. and Henry, D. (eds.), The Worm, the Germ and the Thorn: Pictish and Related Studies Presented to Isabel Henderson. Pinkfoot Press. ISBN1-874012-17-2
2001. Okasha, E. and Forsyth, K., Early Christian inscriptions of Munster: a corpus of the inscribed stones. Cork: Cork University Press. ISBN978-1-85918-170-6
2005. "HIC MEMORIA PERPETUA: the inscribed stones of sub-Roman southern Scotland". In: Foster, S.M. and Cross, M. (eds.) Able Minds and Practised Hands: Scotland's Early Medieval Sculpture in the Twenty-First Century. Society for Medieval Archaeology Monograph Series (23). Society for Medieval Archaeology. ISBN978-1-904350-74-3
2007. "An ogham-inscribed plaque from Bornais, South Uist". In Ballin-Smith, B., Taylor, S. and Williams, G. (eds.), West over Sea: Studies in Scandinavian Sea-Borne Expansion and Settlement Before 1300. Leiden: Brill. ISBN978-90-04-15893-1
2008. Forsyth, K. (ed.), Studies on the Book of Deer. Dublin: Four Courts Press. ISBN978-1-85182-569-1
2011. Barrowman, R.C. and Forsyth, K., "An Ogham-Inscribed Slab from St Ninian’s Isle, Found in 1876". In The Chapel and Burial Ground on St Ninian’s Isle, Shetland. Excavations Past and Present. Society for Medieval Archaeology.