This is the first book illustrating the use of intonation in Northern Vietnamese, based on a hybrid approach combining Conversation Analysis and Laboratory Phonology. The results show that the role of intonation in (Northern) Vietnamese has been greatly underestimated in previous investigations. The interaction between intonation and lexical tone is analysed in the framework of autosegmental phonology. New evidence suggests that the melody at the edges of utterances in Northern Vietnamese can be analysed as a combination of the lexical tone of the final syllable and a boundary or intonational tone used to express communicative functions. The study also has implications for the analysis of intercultural communication.