Por vs Para (Time period)

Por vs Para (Time period)
 

In the sentences below, can 'por' and 'para' be interchanged?
I've always understood the correct term to be 'por', but I have read 'para' in some texts I've come across.

Mi novio ha ido a Francia por un mes.
Mi novio ha ido a Francia para un mes.

Mi novio irá a Francia por un mes.
Mi novio irá a Francia para un mes.

Yo estudié por seis horas.
Yo estudié para seis horas.

Yo voy a estudiar por seis horas.
Yo voy a estudiar para seis horas.

Elena vino por una quincena.
Elena vino para una quincena.

Elena vendrá por una quincena.
Elena viendrá para una quincena.

Many thanks in advance.

To me, "para" sounds incorrect. I cannot know if this is could be used anywhere else though.

"Para", for me, needs that you state a purpose:

-Mi novio fue a Francia para quedarse un mes.
-Mi novio irá a Francia para estar allá un mes.
-Yo estudié para prepararme seis horas antes.
-Yo voy a estudiar para aprovechar estas seis horas.
-Elena vino para pasar una quincena con nosotros.
-Elena vendrá para trabajar una quincena en la empresa.

Thanks so much!

Just looking back on what you said there, AngelicaDeAlquezar...

I have heard Spaniards using para with a time expression:
Mi novio ha ido a Francia para un mes.
Maybe the verb 'pasar' is implied but not stated?

Which is why maybe it wouldn't work below:
Yo voy a estudiar para seis horas. (Again, I'm not sure if this correct, but I don't think it is).

Since I'm really not familiar with the use of "para" in this context, I hope our forum members from Spain will chime in.


I found some examples on Google (not many) where people say "estar para un año" or "estar para dos semanas" and even "estudiar para una hora". I can't tell whether they are foreign learners or if they're native speakers.
So, supposing these are all Spanish native speakers, I guess your examples are alright when used with people who speak like this. In many other environments, you might even get corrected. :thinking: