This collection of funny vituperations against bad grammar was a surprise best-seller in England, where delight is taken in such bracing sentiments as ''If you still persist in writing 'Good food at it's best,' you deserve to be struck by lightning, hacked up on the spot and buried in an unmarked grave.'' Truss is William Safire crossed with John Cleese's Basil Fawlty -- amusingly short-tempered about misplaced apostrophes, commas, and quotation marks. It was unwise, however, to publish Eats on this side of the pond without adjusting its admonitions to U.S. practices. Any Yank confused about where to put a period in quoted dialogue -- for example, ''I said, 'You're nice''' -- will still be confused (and marked incorrect by teachers) after reading Truss' lengthy explanation. Eats works well as a humor book, but not as a remedy for American solecisms.