"To Lie" vs. "To Lay"
The verbs to lie and to lay cause a great deal of confusion. (This discussion focuses on to lie in the sense of “to lie down,” not in the sense of deceiving others.) Although to lie and to lay have related meanings, they are in fact two different verbs with different forms.
To lie is an intransitive verb; it cannot take a direct object. To lay is transitive and thus requires a direct object.
Here are the standard forms for each of the verbs:
|Verb Tense||To Lie||To Lay|
|PRESENT||He lies down.||He lays the book on the table.|
|PAST||He lay down.||He laid the book on the table.|
|PRESENT PERFECT||He has lain down.||He has laid the book on the table.|
As you can see in the table above, the past tense of to lie looks like the present tense of to lay. That similarity is perhaps the source of many of the lie–lay mix-ups.
Please note that it would never be correct to say, I laid down on the bed; the correct past tense form in this case would be lay. Also, don’t tell your dog, “Lay down,” or you risk teaching your pet bad grammar! The correct command is “Lie down.”