Usage and Grammar
Q. When is “lay” or “lie” used?
A. This question lay in our in-box for weeks, where we thought it might lie forever, and where it would have lain indefinitely had we not finally gotten around to answering it. Our first attempt to lay down a response wasn’t very good, so we laid it aside, but even if we’d laid down something worthwhile, we managed to lose it, so your question was still lying in our in-box before we finally succeeded in laying down the response you are reading right now.
As that first paragraph illustrates, the verb “to lie” is intransitive, so it doesn’t take an object; it describes a state of being rather than an action. It’s conjugated lie–lay–lain (for the present tense, past tense, and past participle). The present participle is “lying.”
The verb “to lay,” on the other hand, is transitive (with or without “down”), meaning that it takes an object (on which it acts). It’s conjugated lay–laid–laid. The present participle is “laying.”
So decide which one to use based on the presence or absence of an object. Then choose an appropriate tense and lie back—or lay yourself down if you’re not already prone—and enjoy the feeling that comes from knowing you’ve chosen your words with care.