Yanpeng Sun, PhD ’19, had never been abroad until he came to Harvard from China in 2013 to pursue his doctorate in structural geology. “It was a bit scary at the beginning,” he recalls. Although Sun had started learning English at age 11, he needed to improve his oral skills before assuming his teaching fellow responsibilities.

Thanks to the Bok Center’s Professional Communication Program for International Teachers and Scholars—and with considerable personal drive and support from his faculty advisor—Sun has greatly enhanced his grammar, vocabulary, and conversational...