Grammar Lesson #1: The Difference Between Lie and Lay

Most people use lay to mean both lie and lay. Here’s how it’s supposed to work:

The jargon goes like this: Lie is an intransitive verb. Lay is a transitive verb. This means lay must have a word after it: It does something to something. Think of it this way: It’s transient. It cannot be by itself. Other similar pairs are sit/set and rise/raise.

I sit I set it
I rise I raise it
I lie (down) I lay it (down)

The confusion occurs because the past tense of lie is lay:
Present: Lie Lay
Past: Lay Laid
Participle: (Have) Lain (Have) Laid

So if it’s just you, you lie. If you’re doing it to something, it’s lay.