(Remember, we are talking about lie as in “to recline” and lay as in “to put or place.” The present tense of lie is lie or lying. The present tense of lay is lay or laying.)
To begin the confusion, let’s look at the past tense of lie. The past tense of lie (to recline) is lay — as in “Yesterday afternoon, I lay on my bed for an hour.” Wait! Let me get this straight — the past tense of lie (to recline) is LAY? Yes, as confusing as it may be, lay is the past tense form of to lie (to recline).
The past participle tense (when we use have, has or had) of lie (to recline) is lain — as in “She has lain on the bed all day.”
Got it? Okay, moving on to the verb lay (to put or place):
The past tense of lay (to put or place) is laid — as in “Yesterday afternoon, I laid the folder on your desk.”
And the past participle tense (using have, has or had) of lay (to put or place) is also laid — as in “She had laid the revised proposal on her boss’s desk before leaving for the day.” Well, that is easier to remember because the past tense and the past participle tense are the same word — laid!
For quick reference, I’ve created a little chart to help you keep track of these tricky verbs:

Feel like you’ve got it down or want to see if you can remember which verb and tense is which? Test your knowledge of lie vs. lay in this quiz from GrammarBook.com.
