The transitive verb lay, and lay, the past
tense of the neuter verb lie, are often confounded, though quite
different in meaning. The neuter verb to lie, meaning to lie down or
rest, cannot take the objective after it except with a preposition. We can say
"He lies on the ground," but we cannot say "He lies the ground,"
since the verb is neuter and intransitive and, as such, cannot have a direct
object. With lay it is different. Lay is a transitive verb,
therefore it takes a direct object after it; as "I lay a wager," "I
laid the carpet," etc.
Of a carpet or any inanimate subject we should say, "It
lies on the floor," "A knife lies on the table," not lays. But of
a person we say—"He lays the knife on the table," not "He
lies——." Lay being the past tense of the neuter to
lie (down) we should say, "He lay on the bed," and lain being its
past participle we must also say "He has lain on the bed."
We can say "I lay myself down." "He laid himself down" and
It is imperative to remember in using these verbs that to
lay means to do something, and to lie means to be in a state