I see your comments on a bunch of other manhwas and I always agree facts
In the chapters they said that Salvo is a 'genius' and that he learns really fast that he is confident that he can write a full English book. I assume that he learned some words including sister and also based on the situation he was able to use context clues to understand the situation.
I doubt he learned THAT fast, though. Ben hasn't really started teaching him that much, and Salvo's lived in Florida for a long time and never learned. It's hard to tell since the translator didn't change the color's text based on what languages were being spoken like the other did.
I'm honored! Lemme know the next time we meet.
Salvo doesn't speak English; they even acknowledge this. How did he understand about Ben's sister or his situation? And IDK why he's supposed to be the bad guy in this situation; while what he said was rude, Ben did lie to him and admitted to changing his identity and cutting and running when things got tough.