have to
Van a hacer lo que tengan que hacer.
They're going to do what they have to do.
Ahora, hagan lo que tengan que hacer.
Now, do what you have to do.
— La Caída (2004)
Esperemos que no tengan que hacerlo.
Let's hope they don't have to.
Quizás no tengan que esperar mucho.
They might not have to wait long.
— Estallido mortal (1981)