Lie vs. Lay

The proper use of "lie" and "lay" is tough for English speakers to grasp. We get it wrong all of the time. We use forms of "lie" when we mean "lay" and forms of "lay" when we mean "lie."

Lie: "to assume a horizontal position on a supporting surface" or to tell a lie.
Lay: "to place on a surface."

What does it mean to "conjugate?" "To give the different forms of a verb." Let's conjugate "lie" and "lay" so we can understand what form to use when speaking or writing.

Conjugation of "lie:"
Present                 Past (to take a horizontal position/to tell a lie)
(I) lie                                lay/lied
(You) lie                          lay/lied
(He/She) lies                   lay/lied
(We) lie                            lay/lied
(They) lie                         lay/lied

Participles
Gerund = lying
Past = lain (to take a horizontal position)/lied (to tell a lie)


Conjugation of Lay:
Present                   Past
(I) lay                       laid
(You) lay                  laid
(He/She) lays            laid
(We) lay                   laid
(They) lay                 laid

Participles:
Gerund = laying
Past = laid

Examples:
I am going to lie down for a little while.
She laid the wedding present on the table.

Source: (The Pocket Oxford American Dictionary of Current English. New York, NY: Oxford University Press, 2002, p. 163, 446, and 455)