District Liners sometimes question me about grammar and usage, with special emphasis on things that have appeared in this newspaper.

Unfortunately, there is no supreme authority on English. There is no final arbiter. To form a sound judgment, one must weigh the opinions of many experts. So before I comment on such matters, I discuss them with our Metro copy editors.

On one occasion, the editors I consulted couldn't resist needling me a little. One said, "Those readers of yours are certainly a bunch of nit-pickers. Are all your readers English teachers?"

But another copy editor saved the day for me. He said, "Our readers do appear to be quite demanding and well educated. They pounce on every mistake that gets into the paper. But doggone if I wouldn't rather work for a literate audience than for people who don't know the difference between right and wrong."

I feel the same way. If you do, too, perhaps you'll join me in reviewing some recently arrived questions.

A letter from J.J. referred to a story and headline that said a local doctor had "pleaded innocent" to a charge. There is no such plea, said the letter writer. "The defendant pleaded "not guilty." Why does your paper insist on saying that people pleaded "innocent" when they didn't?"

Let me answer by citing a July 2 news story that, in our first edition, said, "Because the airlines did allow their stewardesses to be married, most quit after about two and a half years to get married." From the context, it is plain that the word "not" was inadvertently omitted between "did" and "allow" (and in the next edition, the missing "not" was inserted).

That was a relatively harmless example of the tendency of little words like "not" to disappear. But if a story gets into type saying "Joe Jones Pleads Guilty" when it was supposed to say "Not Guilty," that's no small matter. So, to minimize the danger of inadvertently damaging Joe Jones or any other defendant, we say "pleaded innocent." In this instance, careful reporting must take precedence over accepted usage.

Ellen Aaron of Arlington sent me two Big George cartoons in which George said he hates "Monday's." Once, says Ellen, the apostrophe could have been a forgivable oversight. But when George keeps on forming plurals by inserting apostrophes, he needs to be told he's wrong.

I agree - even without consulting with my colleagues on the copy desk. George hates Mondays, not Monday's.

Ellen raises another point. In a story about Soviet fighter planes, we called them "Migs."

Ellen says, "There is no such airplane. It is a MiG - upper-case M, lower-case i, upper-case G. The Russians name planes after their designers (in this case, Mikoyan and Gurevich). Similarly, the Tu planes (such as the Tu144) were named after Tupolev, and the Yak planes were designed by Yakoviev."

Well, the ancient enjoinder, is, "Learn one new thing each day" - and I just filled my quota for today. Webster's New World Dictionary confirms Ellen's information about Mikoyan and Gurevich and says the plane is a MIG (all upper-case), "also written MiG." It remains to be seen whether we and other newspapers are now wedded to "Mig," or whether our style mavins will order a change.

(Mavin, incidentally, is spelled with either an e or an i, depending on which mavin on transliteration from Yiddish you consult. The New World prefers maven but accepts mavin. Whatever the spelling, the word means "expert or connoisseur," often a self-proclaimed one.)

Alfred Friendly, managing editor of The Washington Post before his retirement and still a handy man with the English language, now edits our internal style publication, Stylus. In his most recent edition, Friendly notes that a news story contained the line, "I'm not sure who died first, her or the tree."

Friendly's comment was: "Us know. Her did."

Herbert Weiss took me to task for saying, in a column about gasoline supplies, that "some storage tanks are fuller than others." A tank is either full or not, he pointed out, and he is right. It can't be fuller than full.

Earl B. Abrams of Arlington, who is himself a pretty good man with a copy pencil, raised an eyebrow at a recent Post editorial that used the expression "shoulders to the grindstone."

Earl's comment, like Friendly's, was brief: "And nose to the wheel?"

We newspapermen sometimes defend our bloopers by pointing out that we work against daily deadlines. The implication is that those who write books and magazine articles have more time to correct their mistakes. There is some validity to this, but the truth is that we all make mistakes, and the best way to learn is to listen to criticism from others. Remember Gold's Law: "We're all ignorant. We're just ignorant on different subjects."