I grew up in a small city in upstate NY where a lot of eastern Europeans immigrated in the early 20th century up until the second war. Going to my friends' houses in the 80s - it was normal for the extended family to all live under one roof - there were a few families with grandparents who did not speak any English at all, and only spoke Czech, Hungarian, or Polish. Of course, the people these non-English speakers did business with on a daily basis for most of their lives in the US were speakers of those languages, and they could also rely on their children - my friends' parents - to translate.