My estimable colleague Mark Allen, tweeting today as @EditorMark, reminds us: "You 'lay' something. But, annoyingly, 'lay' also is the past tense of 'lie.' Lay an object down. Lie down. He lay down. (It was laid down.)"
I learned the lie/lay distinction in the fifth grade under the firm direction of Mrs. Jessie Perkins, who brooked no dissent over usage, and I have diligently observed it without fail for the past half-century as teacher's pet, college student, graduate student, and copy editor.
But Merriam-Webster's Dictionary of English Usage points out that though the distinction, first established in the eighteenth century, has been maintained stolidly by grammarians, schoolteachers, and editors in formal written English, they have had little effect on spoken usage.
Thus "the conflict between oral use and school instruction has resulted in the distinction between lay and lie becoming a social shibboleth--a marker of class and education."
Whether it is still a useful marker is, I think open for examination. Though the distinction is entrenched in dictionaries and usage manuals, and though the dwindling tribe of copy editors appears to be preserving it in edited published prose (to the extent that published prose is edited), its days look to be numbered, like the days of whom.
Over the past few years, I have reluctantly included lie/lay in my editing class for Loyola Maryland undergraduates, even though it looks as odd to them as Linear B. I am not exaggerating, much. They do not hear the distinction. No matter how many times I review it, they still get it wrong, because laid as past tense and past participle of lie is what sounds natural to them, what sounds like English. And MWDEU suggests that they are in a numerous company.
I've gone so far as to suggest that they tattoo lie lay lain lying lay laid laid laying on their forearms before the final examination, but I have no confidence that that would be of any help to them.
And yet, I've only tiptoed far enough out to tell them that they should know it for the occasions on which they are subject to sticklers, not in their personal usage. I have not had the courage to say they they might as well give up on it altogether, and let the sticklers rage impotently.
What do you think about the matter?