This is the 15870th most frequent Russian word.
пролежал
"Proležal" means "lay for a while" or "remained lying."
In this sentence, 'пролежал' emphasizes a period of time during which the person was in a lying position in the hospital.
Он пролежал в больнице неделю.
He stayed in the hospital for a week.
Here, 'пролежал' refers to spending the evening in a lying position on the couch.
Я пролежал на диване весь вечер, отдыхая.
I laid on the couch all evening, relaxing.
In this example, 'пролежали' is used to indicate the books were on the attic for a long time, emphasizing the duration.