Roy H. Copperud, 76, an authority on the style and usage of the English language. He wrote five acclaimed books, including "American Usage and Style: A Consensus," which won the 1980 Humanities award of the Assn. of American Publishers. Copperud worked as a journalist in Minnesota, Baltimore and Los Angeles where he was a copy editor for The Times. He was editorial director and music critic for the Pasadena Independent and Star-News before becoming a professor of journalism at USC in 1964. He was a member of the usage panel for the American Heritage Dictionary, a consultant to the Webster Living Encyclopedic Dictionary and a cited source in Webster's Dictionary of English Usage. He also was the longtime author of the "Editorial Workshop" column in Editor & Publisher, a trade publication for journalists. In Altadena on Friday of what was described as a lengthy illness.