Lie is a verb that means to rest in a horizontal position or to tell a falsehood. It is an intransitive verb, which means it does not take a direct object; i.e., you cannot lie something else, but you can lie by yourself.
Lay is a verb that means to put down or to place. It is a transitive verb, which means it takes a direct object; i.e., you can lay something else somewhere, but you cannot lay by yourself — unless you’re a chicken, in which case the unmentioned egg would be the direct object.
My mama always told me: “People lie; chickens lay.” Good way to remember it.
But then, the plot thickens….
The confusion gets really bad when you learn that the past tense of “lie” is “lay.”
Example: I lay down for a nap last Saturday afternoon.
This is best illustrated by a little spreadsheet of examples:
|Present Tense||Present Participle||Past Tense||Past Participle|
|People lie down.||People are lying down.||The people lay down.||The people have lain down.|
|People lie (fib) to me.||People are lying to me.||People lied to me.||People have lied to me.|
|Chickens lay eggs.||The chickens are laying eggs.||The chickens laid eggs.||The chickens have laid eggs.|
In the oil patch, you can lay the pipe down. Perhaps yesterday you laid pipe for a new pipeline.
But there is no lying on the job, whether that means resting or telling a fib.