For any language other than english you must define it as a subtitle language.
On "Menu", "Options", "Configuration" in the subtitle section, in the predifined language textbox you have to add the portuguese, either by typing it like "por, eng" in this case for portuguese and english subtitles, or by selecting the language in the button next to it.
If you're in android you must do the same in the options "top right of the screen", but in this case you should change the subtitle encoding to windows-1252 or else all the portuguese special characters like ç and é and so on will be truncated.
hope it helps.
