to let them, to allow them to
Non avrei dovuto lasciarle andare.
I shouldn't have let them go.
In pratica, non devi lasciarle segni.
Basically, you mustn't leave any marks on her.
— Kill Bill: The Whole Bloody Affair (2011)
I can't leave them.
Ti consiglierei di lasciarle andare.
I would advise you to let them go.