What is better to add a new language to an already establish site or to create a new shop-new domain

[HH Services Limited]

Hi everybody,

I have an already establish site using prestashop in english and I would like have a spanish version. If I add a new language in the back office, I am afraid to:

1-Slow down the downloading speed of the english site

2-Create all kinds of redirecting errors and duplicate content errors in google webmasters which it will kill the organic searches for this english shop (the english version will add to the urls /en/  which it will create a new url with the same content as before the url change)

 

Should I add this language in the BO of the english site, or it would be better to purchase a new domain and create the spanish version in a totally new prestashop site?

 

Thank you.

Edited November 6, 2014 by Anthony DeLa Riviere (see edit history)

[shacker]

add into a new domain to keep your current urls