How to edit the errors

Hi,

How i edit the errors showed on website to my language?

Thanks,

Fred

What errors?

What errors?

I give you an exemple:

You must be logged in to acess this feature and stuff like that…

Thanks,

Fred

Check the /core/lang/ files

Check the /core/lang/ files

I already chaged that but, some errors aren’t there.

Thanks,

Fred

Is it possible for a user to change the language of the website? (without using google translate)