they have to do it
Les dejarán ir, tienen que hacerlo si no hay pruebas.
They’ll let them go; they have to if there’s no evidence.
— Caché (Escondido) (2005)
Tienen que hacerlo en el laboratorio del instituto.
They have to do it in the institute's laboratory.
— State and Main (2000)
They have to do it now.
Se supone que tienen que hacerlo ustedes.
You’re supposed to do it yourselves.
Tienen que hacerlo, por el trabajo que hacen.
They have to do it, because of the work they do.
They don't have to do it.