The vast majority of people butcher these two words.
Quite simply, the word lie is an intransitive verb showing that someone or something is in a reclining position. (An intransitive verb cannot take an object, that is, a noun cannot directly attach itself to the word lie.)
The word lay, on the other hand, is a transitive verb showing the act of putting or placing something or someone in a particular position or location. (A transitive verb can take an object, that is, a noun can attach itself to the word lay.)
The child lies on the bed. The parent lays the blanket on the child.
Huge problems arise when these two verbs are inflected:
|Verb||Present Tense||Past Tense||Past Participle||Present Participle|
|lay||lay lays (3rd person)||laid||laid||laying|
|lie||lie lies (3rd person)||lay||lain||lying|
Thus, for lay:
Yesterday, he laid the blanket on the child (past tense of lay).
He has laid the blanket on the child (present-perfect tense using the past participle laid).
When his wife called, he was laying the blanket on the child (past-progressive tense using the present participle laying).
And for lie:
Yesterday, the child lay on the bed (past tense of lie).
The child has lain on the bed (present-perfect tense using the past participle lain).
The child was lying on the bed (past-progressive tense using the present participle lying).
A trick you can use:
The word rise is similar to lie. They both are intransitive. And they both have the “eye” sound. The shade rises and lets in the sun. The child lies on the bed.
The word raise is similar to lay. They both are transitive. And they both have the “long a” sound. She raises the shade. She lays the book on the shelf.
Example: She often lays it there. I laid it there myself just yesterday, and I’ll be laying it there again tomorrow.
Example: She often lies there. I lay there myself just yesterday, and I’ll be lying there again tomorrow.