Korean linguist and language teacher. He is an associate professor of Korean language and linguistics in the Department of Asian Languages and Cultures at the University of Wisconsin-Madison, where he directs the Korean Language Program, and he holds a PhD in linguistics from Indiana University. His work covers Korean linguistics, second language acquisition and textbook design. With Jieun Kim and Ji-Hye Kim he wrote the beginners' course My Korean, published by Routledge in two steps.