Dou Rongyan, 17, was showing American teenagers in Hamburg how to draw Chinese characters and say common phrases.
School "is more fun here," he said during the tutorial one day last week. At his 4,000-student high school in Tianjin, China, "we have to stay very, very long."
The usual school day lasts 11 hours.
"It's a little boring," his friend Li Bingxin added. Her class might have 50 students, but it's never noisy. Here "students can talk to the teacher in class."
The two teens from China's third-largest city were among a dozen pupils who visited Frontier Senior High School last week.
Such exchanges are becoming increasingly common, as schools in China and Western New York seek to give their students a look at the shrinking world that awaits them after graduation.
"What we love is to see our students meeting students from around the world," said Maria Wilcox, head of the International Club.
The Tianjin students' 15-day tour of the United States includes stops in Washington, D.C., and New York City, as well as a frigid look at Niagara Falls and the week in Hamburg.
"The American side can learn that the learning process should be very hard work," said Shuching Chen, executive director of the Center for Cross-Cultural Exchange in Amherst, the coordinator of the visit. "If you want to compete with them, you've got to do things better."
China's rising global importance has prompted one local school to add Mandarin Chinese -- spoken in the capital, Beijing -- to such options as French and Spanish.
The class began last week, at Lewiston-Porter High School in Niagara County, with the help of an instructor from Tianjin. It followed exchange visits like one last February, hosting students from Tianjin.
About 20 miles from China's coast, Tianjin has a long history as a trading center. It also hosted some events during last year's Olympics, based 80 miles away in Beijing.
For the Chinese students, spending time in the United States is an opportunity to sharpen their English skills and learn more about life here. In October, Lake Shore Middle School hosted 26 students from Changchun, China.
The Tianjin students already were well-acquainted with Western culture. They said they liked pizza as well as dumplings; some were fans of the Colombian-born singer Shakira. Everyone had heard of swimmer Michael Phelps and National Basketball Association star Yao Ming.
Rongyan plans to return to study at a university here. The tall boy with the beginnings of a mustache plays basketball and said he hopes to become a scientist.
The visitors stayed with local families, sharing life outside of school hours.
Rongyan stayed at 11th-grader Alex Kirby's house, where the two liked watching YouTube videos. Basketball highlights like moves by Kobe Bryant and Michael Jordan were favorites.
But Alex said he sees one problem with repaying the visit. "They all learn English -- it would be harder for us."
Still, 11th-graders Valerie Mueller and Amy Tighe said they would like to visit China, having begun to learn a few phrases like "ni-hao" [nee-how] for "hello" and "xie-xie" [zhay-zhay] for "thank you."
"I want to hear more of their music," Valerie said. She had listened to her guest's iPod and thought Chinese pop was more musical -- "here it's a lot of rap and talking."