Then there loads
of examples where both shall
and have to can be used.
However, we will find the meaning altered in the two sentences:
shall do your homework.
(2) You must
/ have to do your homework.
shall eat what's on your plate.
(2) You must
/ have to eat what's
on your plate.
The sentences marked with (1)
emphasises the person that demands something. It's the
person's will that the other person does what is requested.
These cases are translated into Spanish usually with
The sentences marked with (2)
emphasises that there is something that makes
it impossible to do something else than the required
action. With an extension of the sentences it will be
shall do your homework and not sleep.
Haz tus tareas y
no duermas. (Do
your homework and don't sleep)
You have to do your homework if you want
to pass this year.
Tienes que hacer
tus tareas, si quieres pasar el año.
You shall eat what's on your plate and not
talk so much.
Come lo que está
sobre tu plato y no hables tanto.
(Eat what's on your plate and don't talk
You have to eat what's on your plate if
you want to become big and strong.
Tienes que comer lo que está sobre
tu plato, si quieres hacerte grande y fuerte.
In the (2.X) marked sentences
shall cannot be substituted by have to anymore. Because
there is no alternative than do what is demanded.