My mother tongue is Pennsylvania Dutch, which I speak to this day with my family and others from the Mennonite community. It is the language of home, socials, and even business so long as all parties understand the language. For religious literature, hymnology, and the Bible, we use the 16th century German of Martin Luther's Bible (1545), which differs significantly from today's official German in Deutschland. Dad taught us this medieval German in German School, and I understand it is still being taught in Amish and Mennonite schools of North America. Our ancestors brought these two languages across the Atlantic to Pennsylvania from Germany in 1683. See https://www.history.com/this-day-in-history/first-mennonites-arrive-in-america. But all of us learned English when we started school. I grew up with these three languages but "Learning English" was a "Rite of Life" passage I will never forget. All my education was in English, from Grade 1 through university, with the exception of Dad's Saturday afternoon German School at the kitchen table.
Today I live in a mid-sized Canadian city of very diverse population, conversing with business people, friends and neighbours who originate from all over this country and the world.