What is the difference between "por" and "desde hace" to express a length of time.

Question

How would you translate "She has been studying for 2 hours" vs. "She studied for two hours" vs. "She had been studying for two hours." When should you use "por" vs. "desde hace"?

Answer 1

Welcome to the site

the present perfect continuous in English is best translated by "llevar + gerundio"

Llevo estudiando inglés desde hace 10 años.

Ella lleva estudiando desde hace tres horas.

But:

Lleva tres horas estudiando.

Lleva dos días durmiendo.

As you can see , we do not use for

Answer 2

She has been studying for two hours: "Ha estado estudiando por dos horas", but you can also say "Ha estado estudiando desde hace dos horas"

She studied for two hours: "Estudió por dos horas", but you CANNOT say "Estudió desde hace dos horas"

Answer 3

The "llevar" construct can certainly be used as described above. However, the fact of the matter is, that in living Latin American Spanish, both "por" and "desde hace" are both used to express lengths of time.

In my opinion (I am a life-long Spanish speaker), "por" is used to express a more definite, generally shorter, length of time, while "desde hace" is used for less definite, generally longer, periods of time. So, in the examples given, "por" could be used in all 3 constructs:

"She has been studying for 2 hours." - Ella ha estado estudiando por dos horas. "She studied for two hours." - Ella estudió por dos horas. "She had been studying for two hours." - Ella estuvo estudiando por dos horas.

Here is an example with "desde hace":

"He has lived in Ecuador for about 11 years." - El ha vivido en Ecuador desde hace once años. This can also be expressed: Lleva once años viviendo en Ecuador.

Answer 4

In my opinion (I am a life-long Spanish speaker), "por" is used to express a more definite, generally shorter, length of time, while "desde hace" is used for less definite, generally longer, periods of time.

We actually don't use por for time sequences in Spain, or hardly ever.

There are many differences between Latin American español and Spanish castellano! :) - waltico, May 22, 2010

Answer 5

Actually, I have just checked, in the dictionary, por is not defined as "sequence of time". I know you use it that way, this doesn't mean you should of course

Answer 6

Ya he contestado, pero es un rollo este chisme....