TO LIE
The verb to lie has two completely different meanings:
1. to lie can mean to tell a falsehood, to tell a lie. The past tense of this verb is lied.
Odysseus lies to the Cyclops, telling him that his name is Noman.
Odysseus lied to the Cyclops, telling him that his name was Noman.
The Cyclops eats two of Odysseus's companions and lies down to take a nap.
Unfortunately, the past tense of this verb is lay. Yes, that is how the confusion starts! So, here is that same sentence in the past tense:
The Cyclops ate two of Odysseus's companions and lay down to take a nap.
TO LAY
So, lay is the past tense of the verb to lie in the sense of to lie down (see the sample sentence above), but to lay is also a verb in English, meaning to place down, to set down, to put down. For example:
The gambler lays his cards on the table.
The chicken lays an egg.
The past tense form of the present-tense verb lay is laid:
The gambler laid his cards on the table.
The chicken laid an egg.
If you are not sure which verb to use, ask yourself whether the verb has an object or not. The verb lay/laid must have an object. You lay SOMETHING or SOMEONE, as when the gambler lays his cards down or the chicken lays an egg:
The gambler lays his cards on the table.
The chicken laid an egg.
The verb lie/lay does not take an object:
The Cyclops lies down and takes a nap.
The Cyclops lay down and took a nap.
Just think about gamblers, chickens, and the sleepy Cyclops, and hopefully you will be able to master this very confusing pair of verbs!