"To Lay" or "To Lie", that is the question

Why is there an image of a pillow on this post? Because authorities say it is the closest pictorial representation I'm allowed to use for the expressions "to lay" and "to lie" - after all, children read this blog.

"To lay" is a transitive verb, which means it requires something - or someone - else to complete the action. "I'm going to lay down this bowling ball because it inhibits my ability to type."

"To lie" is an intransitive verb and it doesn't require anything else to be complete. "I lie down." The only noun is me (or "I" if you want to get technical).

Now here's where it gets tricky (like typing with a bowling ball in one hand): the past tense of "to lie" just happens to be "lay". So, it's grammatically correct to say "Today I lie down" and "Yesterday I lay down." The past participle is "lain" as in "At times, I have lain down" (I say this every day).

The past tense and the past participle of "lay" are both "laid". Therefore, you could say "Today I lay my hat on the cat", "Yesterday I laid my hat on the cat" and "At times I have laid my hat on the cat" - and none of these sentences will warrant you a visit by the grammar police (however, the FBI may contact you for copyright infringement).

Infinitive - Present - Past - Past participle
To Lay - Lay - Laid - Laid
To Lie - Lie - Lay - Lain