If homeboys want to be chillin', that's cool with the National Council of Teachers of English.

Slang is just as important as mastery of standard English, say teachers meeting this weekend in Indianapolis."Youngsters want a distinct identity, so they cook up new ways of using the existing language," said Shirley Haley-James, president of the group that began a four-day conference Thursday in the Indiana Convention Center. "They're saying: `We're not just like our parents.' "

Haley-James, a professor at Georgia State University in Atlanta, and others among the 2,000 educators attending the conference said youngsters should tailor their language to the setting.

"If you go on a job interview and talk this `rap talk,' the interviewer won't think it's appropriate," said John S. Mayher, an English professor at New York University.

Desiree Elliott, a teacher of English at Arsenal Technical High School in Indianapolis, said educators can help teenagers determine when not to use slang.

"I try to keep up-to-date so I can use slang with kids when it's appropriate," she said. "But kids have to understand they must master standard grammar in order to succeed in the world."

Teenage slang, which now draws heavily from urban-oriented rap music, changes frequently, often by generation. Terms that had one meaning years ago sometimes re-emerge with new definitions.

For example, 1950s teenagers described angry parents or friends as being "sore" with them. The term now is used in its more familiar context as a description of pain.

In the 1970s, youths "cracked on" somebody when expressing romantic interest in a member of the opposite sex. Now, it's a definition for talking disparagingly about someone.

Homeboys chillin' out can mean neighborhood friends taking it easy.

But such language often keeps educators guessing.

"We're always behind," Mayher said. "Dictionaries of teenage language always crop up, but they're always wrong. Teenagers change their language when adults finally figure out how they talk."