Hi, my wordpress install has as a main language Spanish and I want the forum to show the same language, but some parts of the forum are still showing English like the (forum navigation menu) and when registering the forum policy and rules text are also in English. Where or how can I change manually this text?
That because the Spanish translation PO/MO is not complete. WordPress plugins translation is made by users and people translate those as much as they can. You can complete translation using PO/Mo files or wpForo Phrase system. Please follow to these instruction:
There is no XML file for Spanish and you don't need Spanish XML. If you change your WordPress language ot Spanish wpForo will automatically load the Spanish po/mo file. wpForo already contains Spanish translation po/mo files by they are not complete, you may need to complete them using Poedit software or method is to use a plugin called Loco Translate.
Also wpForo allows you to do a quick translation of front-end phrases by editing and phrases and changing the values to Spanish phrases in Dashboard > Forums > Phrases admin page.