Im not sure what the reason for changing the name to an English equivalent is? People dont generally do this in reality and it would be great to actually see the nominative of the name in the english version
I don't know if this is a new addition, but my answer was accepted when I wrote Marta instead.
Oh wow, I just listened, heard "nie znam Marty" and got it wrong (did not hear znamY).
"Marty" comes from "Martin", so it's masculine and therefore would be "Nie znamy Marty'ego".
We decided to use the exact same name in English as in Polish, after all you don't change your name after you travel or even move to another country. But "Martha" is accepted.
In Nominative, the same. But even foreign names undergo declension. Well, feminine names NOT ending with -a stay the same, but Martha does end with -a. So in this sentence it would be "Nie znamy Marthy".