Sounds ridiculous, doesn’t it? We all know Dylan’s song — it’s “Lay Lady Lay,” with no commas (although there should be, rightfully), and the verb form is incorrect, but hey. Dylan.
By request (you know who you are!), I’m revisiting lie/lay. I’ve written at least two usage tips about this at G+, but now my explanation will be immortalized here at the blog. (Until someone nukes the site, anyway.) So, without further ado . . .
Lie is an intransitive verb. That means there’s no direct object acted upon by the subject of the verb. In other words, you don’t lie a book on a table. (That sounds ridiculous, too, doesn’t it?) The forms of lie are lie, lay, and lain. I lie down when I’m tired. I lay down for a while yesterday afternoon. I have lain down on many occasions. (I won’t go into the discussion of the propriety of “down” in this construction. Clearly, one can’t lie up, but there is the phrase “laid up,” which is an idiomatic expression meaning “unable to function due to an injury or illness,” often equating to “lying down because standing up is painful.” Gotta love it, don’t we?)
Lay is a transitive verb. That means it takes a direct object, the thing being acted on by the subject of the verb. The action is being transferred (transitive, transfer — see?) to the object. The forms of lay are lay, laid, and laid. I lay the shirt on a towel on the table, because I don’t have an ironing board. (I’m acting on that shirt by laying it on the table.) I laid a book on that table yesterday, and now I can’t find it. I have laid things all over this house, for that matter. Some dialects use “lay” for “lie” and add a reflexive pronoun, like this: “I lay myself down.” It’s even in a very common bedtime prayer, in a slightly different form: “Now I lay me down to sleep.”
I lie, you lie, she/he/it lies, they lie, we lie are the present-tense (root) forms for “lie.”
I lay, you lay, she/he/it lay, they lay, we lay are the simple past forms for “lie.” “The dog lay motionless in the middle of the street.” Note there is no -s on the end of this form. She lay, he lay, it lay.
I have lain, you have lain, she/he/it has lain, they have lain, we have lain are the past participle forms for “lie.” (Note that only the third-person singular takes “has” as the auxiliary verb; all others take “have.”)
I lay, you lay, she/he/it lays, they lay, we lay are the present-tense (root) forms for “lay.” Note the s on the end of the third-person form: She lays, he lays, it lays. “The dog lays a bone at its master’s feet.” It’s easy to confuse this with “lay” (the past tense of “lie”) if you’re not paying attention to the meaning.
I laid, you laid, she/he/it laid, they laid, we laid are the simple past forms for “lay.”
I have laid, you have laid, she/he/it has laid, they have laid, we have laid are the past participle forms for “lay.” The same as with “lain,” only the third-person singular form takes “has.”
Now that I’ve laid that all out for you, I might lie down for a bit.