Just one thing. Looking at the French translation,
"C'est tout ce que je sais dire en anglais, d'accord?"
I think it means
"This is all I know to say in English, Ok?"
Hi Madeleine,
I did the translation from the original in Portuguese, however what matters is not using the exact words, but the form that would be more natural in English keeping the meaning of the original.
Your version is correct too, but that "to say" is not necessary.