When Caren Berg told colleagues at a recent staff meeting, "There's new people you should meet," her boss Don Silver broke in, says Ms. Berg, a senior vice president at a Fort Lauderdale, Fla., marketing and crisis-communications company.

"I cringe every time I hear" people misuse "is" for "are," Mr. Silver says. The company's chief operations officer, Mr. Silver also hammers interns to stop peppering sentences with "like." For years, he imposed a 25-cent fine on new hires for each offense. "I am losing the battle," he says.