to have left it
I thought I made that clear.
Debo de haberlo dejado en el lugar equivocado.
I must have left it in the wrong place.
No puede haberlo dejado en el aeropuerto.
He can't have left it at the airport.
Debo haberlo dejado en el autobús.
I must have left it on the bus.
Alguien debe haberlo dejado ahí.
Someone must have left it there.