THE CAREFUL WRITER by Theodore M. Bernstein. 487 pages. Atheneum. $7.95.
Almost anyone can spot the glaring flaws in this sentence: "I ain't got no pencil." But the English language can set subtler traps. What's the difference, for instance, between sewerage and sewage? Is the word "whereabouts" singular or plural? When does a pupil become a student? Find the errors in these sentences: "Dave Beck pleaded innocent today to a charge of grand larceny." "At least twelve hawks are making their homes atop city skyscrapers and zooming down to snatch pigeons." "Mr. Smith was changing a flat tire when a second car...