LAST week, toward the end of my column about wormholes in certain Supreme Court rulings and correspondence, I said that the unnamed letter-writer who brought them to my attention asked this devilishly equivocal grammar question: “What should the verb be in this sentence: ‘He insisted that she (stay, stays or stayed) in the house’?”

I replied that the answer could be the subjunctive “stay,” the indicative present-tense “stays,” or the indicative past-tense “stayed.” Since the explanation would involve some grammatical complexities, however, I decided to devote a separate column to it.