COLLEGE PARK -- The "Chinese police" at the University of Maryland at College Park don't carry guns or wear uniforms, but they make sure English isn't spoken, and the participants in an intensive language course wouldn't want things any other way.
"If they hear one of us slipping into English, they'll come up and say, 'I don't hear you,' in Chinese," said Floyd Chamberlin, who teaches languages at Southport High School in Indianapolis. "It's all good-natured. It's always done with a smile on their faces."
The four mentors who double as the Chinese police are part of a four-week program that had 17 teachers from around the country learning to speak, read, write -- while they basically lived the Chinese language and culture.
The National Endowment for the Humanities contributed $425,000 to set up the Maryland Summer Institute for Teachers of Chinese to meet increasing demand for instruction in the language spoken by 1 billion people. The 17 completed the program a week ago.
The National Foreign Language Center in Washington said the numbers of Americans learning Chinese have increased sharply in the past 20 years. The center estimates that there are now 200 schools -- mostly high schools -- that have a Chinese language program and about 20,000 college students studying the language, said A. Ronald Walton, deputy director of the foreign language center.
More high school students are signing up for Chinese classes because it is different from the Spanish, French and German traditionally taught, said Stuart Sargent, the project's coordinator.
As more and more high school students sign up for Chinese classes, teachers need to be better prepared. The program is trying to increase the teachers' knowledge of not only the language, but also the culture, said Mr. Sargent, an associate professor of East Asian languages at College Park.
"There aren't many teachers who can teach classes in Chinese. This program has given me more depth, more vocabulary, just a better hold on the language," said Claire Kotenbeutel, a language teacher from Madison, Wis.
The participants spent mornings in language classes and afternoons in lectures on culture, economics and politics of China.
But participants said some of the most intensive learning occurred at night.
"Our teachers have been good, but the best language comes at night with the mentors," said Mrs. Kotenbeutel, who has been teaching for 25 years. "Just speaking the language with the mentors and asking them questions about the culture."
The mentors were busy answering questions long after the day's classes were over.
"There are many nights when I don't go to sleep before 2 a.m. because one will come and ask questions at 11 and the next will come at 12 and another after that," said Diana Zhang, a mentor.
But Ms. Zhang said she likes helping the U.S. students learn Chinese and she is impressed by participants' motivation.
"I'm always amazed seeing Americans learning to speak Chinese. They really have a lot of guts to do this," said Ms. Zhang, a comparative education graduate student at College Park.
The National Foreign Language Center has four difficulty classifications for foreign language -- Chinese is in the hardest category along with Japanese, Korean and Arabic. The languages that have been traditionally taught in high schools for decades -- Spanish, German and French -- fall in the easiest category.
Mr. Walton said the Romance languages Spanish and French are more easily learned because they are similar to English.
Words in Spanish like "matematica" and "importante" can be translated into "mathematics" and "important" by those who have never studied the language. The Chinese equivalents would not be understood.
"Any of the Romance languages have similarities not only in the language but also in the culture," he said. "Chinese has an unrelated culture. The language codes can be hard, but the culture can be 10 times harder."
Mr. Walton said as China becomes more of a world leader, opportunities for employment will open in China, and Americans will need to know the language.
Next summer, another group will converge on College Park to study Chinese language and culture, while this year's group goes to Taiwan to continue its studies for seven weeks.
The second group will go to Taiwan in 1993 and both groups will meet later that year in College Park to evaluate the program.
After spending four weeks at College Park's Language House, Floyd Chamberlin will be able to tell his high school class to quiet down in Chinese, not just in French or English.
"Small talk is important in teaching. The textbooks that I teach from don't give me little phrases," said Mr. Chamberlin. "I would love to say to one of my students, 'What's wrong?' or 'Why are you late?' in Chinese."
Now he can.