When To Use "Lay" vs. "Lie"

Hello, all! Long time no see. Don't worry, I haven't stopped learning things. I've simply run out of time to share them. :)

To catch you up, I am going to make a flurry of posts describing a couple of the things I've learned over the past six months from my favorite little magazine, Reader's Digest. It's always jam-packed with interesting facts. Hope you get to learn something, too!

This first post is about something I know I get wrong all of the time: using "lay" and "lie" correctly.

Here's an excerpt from Reader's Digest's "Word Power" from last summer:

This month, we revisit lay and lie, specifically in the phrase lay/lie low. Lie low is the correct present-tense form. Why? Standard usage still applies: Lie doesn't require an object ("go lie down"); lay does ("lay your head down"). In the past tense, lie becomes lay; lay becomes laid. So a wily predator might lie low as it stalks its prey.

To further this point, I found these rules on The Grammar Curmudgeon website:

1. Lie: "to recline" or "to rest", with no object.
present: lie
past: lay
present participle: lying
past participle: lain

2. Lie: "to tell an untruth"

present: lie
present participle: lying
past/past participle: lied

3. Lay: "to put" or "to place", with an object.

present: lay
present participle: laying
past/past participle: laid

Examples the site gives:

- Once you lay (place) a book on the desk, it is lying (resting) there.  - For your vacation, you spend your time lying (reclining) on the beach [to get a suntan].  - You lie down (recline) on the sofa to watch TV and spend the entire evening lying (reclining) there  - If you see something lying on the ground, it is just resting there; if you see something laying on the ground, it must be doing something else, such as "laying eggs". I think I just need to make myself some flash cards. :)