I am not sure I understand your question, but in my case I am using FM on a Mac with Dutch as the default language.
I prefer to use FileMaker in English so I went to the FileMaker application in the Programs folder and right clicked on
the FM aplication and choose 'Show Package Contents' In the Resources folder are the folders for the different languages.
If you remove the one your systems uses, (in your case Portuguese) FileMaker will use its standard language which is English.
Hope that helps,
Ruben van den Boogaard
Or you could remove all of the dictionaries you don't want used, and FM should let you use the one you leave in place.
Tks Stephen and Ruben.