Lay vs. Lie: Dog Day Afternoon

Samantha writes:

"I wrote an essay for my Language Arts class that included this sentence:

The tired dogs lay in the grass.

My teacher crossed out lay and wrote lie.  Am I wrong, or is she?"

People mix up lay and lie all the time because they both convey a similar sense of reclining or being at rest. But there is a key difference.

Quick rule:

• Lay is a transitive verb. Use it when you have a direct object. I lay my keys on the table. She lays her head on the pillow.
• Lie is an intransitive verb. Use it when you don't have a direct object. I'm going to lie down on the couch. He likes to lie on the grass and look at the sky.

When things get tricky: Be careful about tenses. Lay in the present tense looks identical to lie in the past tense.

• Present tense: I lie on the couch.  
• Past tense: I lay on the couch.
• Present tense: I lay my weary body on the couch.

So the key question is: Which tense?

• If Samantha was using the present tense, then her teacher is correct. The tired dogs lie in the grass. 
• If Samantha was writing in the past tense, then she was correct. The tired dogs lay in the grass.
  

Examples (using present, past, and past participle):

• I lie on the bed. I lay on the bed. I have lain on the bed.
• He lays his cards on the table. He laid his cards on the table. He has laid his cards on the table.

Photo: Pink Sherbet Photography/Flickr Creative Commons