Ray Clark, author of The Vocabulary of Shopping, was on the staff of the School for International Training in Vermont, USA for over 30 years as a teacher trainer for Peace Corps programs in Iran, India, and Korea, as an ESL teacher, as the director of SIT's intensive English program, as a faculty member and director of the MATESL Program, and as teacher-Director of ESP programs in Islamabad, and Istanbul. He has also done teacher training for Marlboro College and Southern New Hampshire University's MATESL program in Hanoi, Vietnam. He has authored numerous well-known books for Pro Lingua Learning.