SIR: In a recent essay on baseball, George Will wrote: "The commissioner's office is one of those institutions that is . . ." I cannot believe Will would make an error, but shouldn't it be "one of those institutions that are . . ."? - Deeply Shaken.

ANSWER: Contrary to what many people believe, even George Will makes errors, and this is one. Turn the sentence around and you'll see: Of those institutions that are whatever, the commissioner's office is one.The one-of-those error is so often committed - even by George Will, think of it - that some authorities have said shucks, we might as well say it's all right even if it isn't. But I am one of those opposed to that position. If a thing is so clearly and outrageously wrong, then it's wrong whoever is guilty.

Let us turn now to another famous exemplar of good usage.

SIR: Ed McMahon is always saying in television commercials, "If you or someone you love is age 50 to 80 . . ." I always have an uncontrollable urge to shout, "I is! I is!" Surely Ed is wrong. - G.M.

ANSWER: Yes and no. When you use "or" to join two subjects, one requiring a plural verb (you are) and the other requiring a singular verb (someone is), the rule is that the verb agrees with the nearer subject (someone), which makes Ed right. But the corollary rule is that such a construction should be avoided whenever possible, because it sounds so terrible, which makes Ed wrong. It's a pity writers of commercials inflict such a maddening construction on our ears. How about: "If you or any persons you love are . . ."

SHARP COMMENT of the week, from M.S.: "My newspaper had a headline saying, `Quorum Court Talks Solid Waste.' I think it is a shame for editorial opinions to creep into the headlines."

Send questions, comments, and good and bad examples to Lydel Sims, Watch Your Language, P.O. Box 161280, Memphis, TN 38186. If you quote a book, please give author, title and page number. Sorry, but questions can be answered only through this column.