Oral history in Dughore recounts that the northwest, northeast and southeast of Kolombangara had their own languages, which became extinct when the people of those areas were annihilated in warfare that probably occurred in the early 19th century.
Inter-island exchange with neighbouring island language areas of Vella Lavella, Simbo and Roviana was strong in the latter 19th century, possibly leading to some language borrowing, although marriage remained largely endogamous at that time.