on the back
He lay down on his back.
Non crede veramente che la porterò in giro sulla schiena?
You don't really think I'm going to carry her around on my back, do you?
— Tre uomini in fuga (1966)
Da bambino ero solito sdraiarmi sulla schiena e guardare le nuvole bianche.
As a child I used to lie on my back and look at the white clouds.
He was lying on his back.
Si sdraiò sulla schiena e guardò il cielo.
He lay down on his back and looked at the sky.
Guarda la scritta che ha sulla schiena.
Look at the writing on his back.
— La vita straordinaria di David Copperfield (2019)