how to help friend: likes girl but language barrier occurs

my (22nb, 22ftm[?]) friend mark (20m) lived in poland since he was 4. he speaks russian, polish, and english.

his English isn’t the best sometimes, and he has foreign accent. he is in love with a woman (24f) he wants to date, but she only speaks English and his family only speaks russian and polish too. he is almost always talking to family on call the whole time in russian, and it gets awkward because she also can’t understand it.