How to change DocBook default language

[Masashi <ricardomaeda@gmail.com>]

Hi, Everybody,

Sorry if this a very basic question. 

I'm a very beginner user in a long searching over tons of google pages, but I just can't find a feature/package/funtionality/etc that would change my Docbook document in another language.

For example, how can I configure my text processor (I use docbook2pdf from docbook-utils-pdf package) to print instead of "Chapter" the word "Capítulo", or "Summary" become "Sumário" in Portuguese?

Thanks a lot.

Best Regards.

Ricardo Maeda.