New Zealand English--at only 150 years old--is one of the newest varieties of English, and is unique in that its full history and development are documented in extensive audio-recordings. This book examines and analyzes the extensive linguistic changes New Zealand English has undergone over the past 150 years on the basis of these recordings. The authors, experts in phonetics and sociolinguistics, use the data to test previous explanations for new dialect formation, and to challenge current claims about the nature of language change.