SIR: I grew up using the expression "amn't I" as a contraction for "am I not." If we don't use "are I not," why do we use "aren't I" rather than "amn't I"? I am correct in using "amn't I," amn't I? - Ruth S.

ANSWER: That's a tough one. "Amn't I" is used in Scotland and Ireland, but elsewhere it's been dismissed by authorities as foreign to the tongue. "Aren't I" is, of course, indefensible, though it's widely used. "Ain't I," the obvious solution, is considered simply wretched by English teachers and has never gained the seal of approval.My own preference, which is admittedly sinful, is to use "ain't" not only for "am not" but also for "are not," "is not," "has not" and "have not." Some day that's how it will be - but we're going to be long gone before it happens, ain't we?

SIR: What happened to the letter "g"? Headache-remedy and denture-cleaning products scream to me from radio and television that they are "extra-strenth." You can't cure this, I know, but can you say something to make me feel better? - M.G.

ANSWER: No, but I can say something to make you feel worse. Many dictionaries list "strenth" as an alternate pronunciation. That's terrible, of course, but at least we don't have to like it. Or even agree with it.

PUZZLED COMMENT of the week, from Claire G.:

"My newspaper had an article referring to `the upstart of the new school year.' I knew pupils could be upstarts, but when the school year itself becomes one, we're in real trouble."

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.

- Lydel Sims of The Commercial Appeal in Memphis writes this column weekly.