LIE versus LAY
1. PAST TENSE: Sometimes memorization is just best
- She lay down on her sofa to read.
- She laid the book on the table, I swear.
- She was lying on the carpet when it happened.
2. PRESENT TENSE: Remember that the gerund form (WAS –ING) uses present tense.
- She was laying down on her sofa to take a nap when the house exploded.
- She was lying on the carpet when it happened.
- She was ating on the floor (no, so it couldn't be laying)
- She was eating on the floor (yes, so she was lying on the floor)