My wife and I took on a translation job recently (we translated a Chinese novel into English). As usual, she did the first translation draft, while I polish up the prose (some Chinese concepts and words do not translate well to English, so prose changes are necessary for such changes). In the process of translation, she encountered many cases of the use of lie, which has also confused my pupils in the past. I had to keep making changes when editing her translation.
Now, when are all the lie, lay, lied and laid used? The hurdle to cross in understanding how it all works lies (yea, a pun) in this one very important concept – lie and lay are words which are homographs* within of themselves.
When lie is used to mean “tell something untruthful deliberately”, both the simple past and the past participle form is lied.
Johnny has lied before to his mother and he lied again to her yesterday. Yes, he lies.
When lie is used to mean “relax on one side of the body”, the simple past form is lay and the past participle form is lain.
My wife has lain with me for 12 years. My son John snuggled and lay with me in bed this morning. Right now, I am trying to get my firstborn Paul to lie down and sleep!
When lay is used to mean “deliver something on the ground”, both the simple past and the past participle form is laid.
Chickens have laid eggs for years. Today, they lay them in huge factories, in terrible conditions. It is so different from just a hundred years ago when they laid them on free-ranging farms.
Hopefully, my post would clear up some confusion, and be helpful to users of English! All these are from your friendly neighborhood English teacher.