In the 19th century many Ngāi Tahu, particularly in the southernmost reaches of the South Island, spoke a distinct dialect of the Māori language, sometimes referred to as "Southern Māori", which was so different from the northern version of the language that missionary Rev. James Watkin, based at Karitane found materials prepared by North Island missions could not be used in Otago. However, from the 20th century to the early 21st century, the dialect came close to extinction and was officially discouraged.