"We're open to English the way people really talk as opposed to what the textbooks say," Kelly said.
SLANGuage's purpose is to help students from abroad, who make up about 15 percent of Penn's enrollment, feel comfortable in their new environment and communicate in social settings. Kelly said he hadn't heard of this type of informal class at other universities. Christian Association executive director Rob Gurnee called it unique.
While participants may ask whatever they want about English, the class is not about the crass lingo that many think of as slang. SLANGuage is as much about culture as it is about words.
"We're not telling people what to believe, but we're trying to explain American culture," Kelly said, adding that the class often focused on holidays, popular music, comics, and the news of the day.
Sometimes the conversation does turn to campus jargon. Long Yun, 45, who was a visiting scholar at Penn's Annenberg School last year and attended 30 SLANGuage classes, said learning slang had helped her in her formal studies.
"So when Bill taught us the popular words hook up, I got it quickly and used it to describe the current cultural phenomenon," she wrote in an e-mail from her home city, Beijing, where she teaches at the Communication University of China.
A recent class, which included Kelly's 400th student, started with a discussion of Thanksgiving and the differences between religious and secular holidays. Emphasizing the importance of family during the holiday, Kelly said he had taken his grandchildren to the new Harry Potter movie and to the battleship in Camden over the weekend. One student shared that he was helping to create an Urdu version of the Encyclopedia of Islam. (Remember the board?)