Within the tourism and hospitality industry in Vietnam, English is now a dominant means of communication between staff and guests who come from different countries. The ability to communicate effectively in English is therefore an important attribute for those employed within the industry. Courses in English for Specific Purposes (ESP), such as English for Tourism and Hotel (English for Tourism Management/English for Hotel Management), are now part of English language programmes in Vietnamese educational institutions. These courses emphasise the importance of developing high-level English language communication skills for students.However, the teaching of these courses has mainly been conducted in the classroom environment, using textbooks which are written and published outside Vietnam. Given that recent research has focused on the need to teach language as it is used in authentic contexts, it is important for the teaching of ESP to understand how English is used in a real-life setting in the Vietnamese tourism and hospitality sector.This paper reports on the findings from a study which obtained and analysed hundreds of examples of authentic English language used by guests and staff in four different hotels in Vietnam. For illustrative purposes, the paper focuses on the language of interactions related to currency exchange, and examines the implications of the study findings for the teaching of ESP in Vietnam.