No lie: It’s lying
If cavemen can get their grammar right, so can we. Many of us, it seems, have a hard time remembering the difference between lying and laying.
As it is used in the cartoon, lying is the present participle of the intransitive verb lie. An intransitive verb is associated with only one noun and cannot take a direct object. A transitive verb is associated with more than one noun and can take a direct object.
Examples: The baby is lying comfortably. The mother gently lays the baby down onto the changing table.
The first sentence has no direct object. Lying, the verb, is associated with the simple subject, baby. Lying has a helping verb, is, in front of it. In the second sentence baby is the direct object and mother is the simple subject. The verb lays is associated with both nouns. It is a transitive verb.
For more examples of the difference between lie and lay, check out http://www.learningtreasures.com/lay_lie.html