I will try to explain again:

The theme files are in English, I want it in my language en_US

see the print: This in English, I want to be in Portuguese
The theme of the announcement says it has translation Portuguese see

http://www.casimages.com.br/i/150515013631925434.jpg.html

And in this admin in English see:

http://www.casimages.com.br/i/150515014158176418.jpg.html

Note that the WordPress menu already in porutguese Brazil, but the theme files not.