Like many fine grammatical distinctions, the discrete uses of “lie” and “lay” as well as of “who” and “whom” are disappearing from the language. There are those of us, however—call us pedants if you wish—who cling to the niceties of the English language. With this in mind, I shall try to clarify the usages of these words.
LIE AND LAY
To put it simply: “lay” is a transitive verb and “lie” is an intransitive verb. (Not to be confused with the noun or verb “lie”, meaning a prevarication or to prevaricate.
I have found that terms like “transitive” and “intransitive” leave most people under the age of fifty scratching their heads, allow me to explain. A transitive verb is an action word that takes a direct object. In other words, it is a word that denotes an action performed directly upon an object, be that a person, place, or thing (a noun). An intransitive verb does not take a direct object.
Hence: To “lie down” implies an action sufficient unto itself. “His missing overcoat lies on the chair.” To “lay something down” implies an action performed upon an object (“something”). “Please lay your coat upon the chair.” Simple, eh?
The problem arises in the past tense. The past tense of “lie” is “lay”. “Yesterday, his overcoat lay on the chair.” The past tense of “lay” is “laid”. “Yesterday, he laid his overcoat on the chair.”
The past participles of these troublesome verbs are “lain” and “laid”. “His overcoat has often lain on the chair.” “He has often laid his overcoat on the chair.”
Here’s a simple diagram:
And another set of examples:
Now, I lay the book upon the table. (I am laying the book upon the table.)
Today, the book lies on the table. (The book is lying on the table.) [Note the spelling change.]
Yesterday, I laid a book upon the table.
Yesterday, a book lay on the table.
In the past, I have often laid my books upon the table.
In the past, several books have lain on the table.
Try making up some sentences of your own, remembering that “lay” is also used as a noun, as in “The lay of the land” or “A good lay.”
Don’t get confused by the bedtime prayer: Now I lay me down to sleep … “. Simple enough. Here “lay” is the transitive verb because “me” is the object of the laying. This sentence means the same thing: Now I lie down to sleep. It’s just not as poetic.
WHO AND WHOM
Now that you understand the difference between transitive and intransitive, you can easily understand “direct object.” “Whom” is always a direct object and “who” isn’t. (Note: “Whom” becomes an indirect object when combined with “to” in a prepositional phrase.)
Here are some examples:
Who is that person to whom you were speaking? (“whom” is the object of the preposition “to”.)
To whom should I address my letter?
Whom did the dog bite? (The dog bit whom?)
Who bit the dog?
It can become confusing when “who” or “whom” or “whoever” or “whomever” are used in subordinate clauses. For example:
Please give this note to whoever answers the door. (“whoever” is the subject of the clause “whoever answers the door” and the whole clause is the object of the preposition “to”.)
Please give this note to whomever. (“whomever” now stands alone as the object of the preposition.)
Who is it that we are going to visit?
Whom are we going to visit?
It just takes some practice. Of course, you are now permitted to make yourself obnoxious by correcting other people’s erroneous usage.
Another time, perhaps, we’ll tackle “like” and “as”.
The famous little book “The Elements of Style” by Strunk and White is not only enlightening on these and other matters but also quite entertaining