Hello
@henrique.coelho I did some small changes in the pt_BR.po file, but I was not able to confirm them.

@cottrell I did try to force the language to Portuguese Brasil, but never got to see it. Always pt_PT was shown.

$ locale
LANG=pt_BR
LC_CTYPE="pt_BR"
LC_NUMERIC="pt_BR"
LC_TIME="pt_BR"
LC_COLLATE="pt_BR"
LC_MONETARY="pt_BR"
LC_MESSAGES="pt_BR"
LC_PAPER="pt_BR"
LC_NAME="pt_BR"
LC_ADDRESS="pt_BR"
LC_TELEPHONE="pt_BR"
LC_MEASUREMENT="pt_BR"
LC_IDENTIFICATION="pt_BR"
LC_ALL=
[helio@localhos]$ export LANG=pt_BR  && gretl

This is Fedora 32.

Cheers.