NEW ZEALAND ENGLISH is one of the most closely studied national varieties of English outside of the USA and UK, and a source of significance for the dialect differentiation and historical evolution of English. Most of the work has been done in the relatively short period of about 15 years compared with the longer time frame of studies in British and American English. One reason for this is that New Zealand English has, from its beginning, benefited from significant co-operative and collaborative activity among New Zealand linguists.