I must not; I don't have to
I must not be disturbed.
I must not speak to you.
Non devo dimenticare di comprare il latte tornando a casa.
I mustn't forget to buy milk on the way home.
Non devo perdere l'autobus delle sette altrimenti arrivo tardi.
I mustn't miss the seven o'clock bus or I'll be late.
Non devo ricordarlo più perché mai mi ha lasciato.
I don't have to remember him anymore because he never left me.
— Still Life (2006)
I don't have to sell my house.