IN a rejoinder to my column that made a quick review of the perfect tenses (“What a sentence needs to take a true perfect tense,” December 5), Miss Mae, a member of Jose Carillo’s English Forum, made three conclusions about their usage that were rather fragmentary. I therefore started a full-dress review of the perfect tenses last week, emphasizing that they (a) indicate that an action or circumstance occurred before another event or point in time, and (b) focus attention on the outcome of that occurrence rather than on that occurrence itself.

One of Miss Mae’s slippery conclusions was that the present perfect tense is used “when it is unknown when the action was completed.” To put that conclusion in the proper perspective, let’s now take up the specific uses and workings of the present perfect.