There are more cases
in which both is possible. When we have a look at the
beginning and the first sentences once more (just before
it gets too pedantic ;-))
Example
(1) Has
somebody fainted, he has to be helped. = Si alguien se desmayó,
se le tiene que ayudar. (2) Has
somebody fainted, he should be helped.
= Si alguien se desmayó, se debe
ayudarle.
The question is who says so?
There are
two interpretations possible for (1) => the higher
institution says so
a) According
to the law everybody who faints has to be
helped, because otherwise it is a relevant
case for failing to render assistance in
an emergency and can be prosecuted. = Según el
código penal se tiene que (hay que)
ayudar a una persona que se desmayó,
si no es omisión de socorro. b)But
also from the moral point of view he has
to be helped, clearly.
= Desde el punto de vista moral está
claro, que se tiene que ayudar a una persona
que se desmayó.
In case
(2) the answer could be
My uncle says that a person should be helped
if he faints
= Mi tío dice, que se debe ayudar a una
persona que se desmayó.
1) no freedom of choice => the law says so
2) hardly any freedom of choice => moral obligation
3) there is freedom of choice => somebody demands
something
The Spanish follows exactly this logic. The differences
between the two possibilities are quite small and usually
are hardly noticed.
Example
Es por eso que la
educación no debe ser tan sólo
una prioridad nacional.
¡Ella debe ser la verdadera obsesión
nacional!
= Therefore the education should not only
be a national priority.
It should be the real national obsession! Es por eso que la
educación no tiene que ser tan sólo
una prioridad nacional.
¡Ella tiene que ser la verdadera obsesión
nacional!
= Therefore the education not only has to
be the national priority.
It has to be the national obsession!
Example
El
horario tiene que ser flexible y realista,
esto significa que no tiene que ser tan
duro que sea imposible de cumplir.
= The schedule has to be flexible and realistic,
that means that it must not be so hard that
it would be impossible to accomplish.. El horario debe ser
flexible y realista,
esto significa que no tiene que ser tan
duro que sea imposible de cumplir. = The schedule
should be flexible and realistic,
that means that it must not be so hard that
it would be impossible to accomplish..
