English is DUMB.


I lie down, you lay me down, she'll lie down, he'll lay her down,  I'd lain there all day, She's (has) lain there all day, I am lying down, She's (is) lying down. 

I lay the book down, I (have) laid the book down, He'll lay the book down, I've laid the book down, He's (has) laid the book down, I'm laying the book down, He's (is) laying the book down.