My wife’s mother was Alsatian. Apparently in Alsace they spoke a form of “low German”, or at least according to her it was so.
But English is also about 1/3 Old French in origin. A quick story. I took French in college and wasn’t too bad at it. My wife and I once took a trip to Ste Barthelemy. I found that I had immense difficulty understanding the French tourists, but not the locals. Turns out the locals were all from Normandy about 300 years ago. They spoke French, and no doubt about it, but there was something about the way they said it that was easier to understand.
I once discussed with a very good certified translator whose first language was not English, what the most difficult part of translation was for her. She said it was at business meetings when people took an informal break. When English speakers speak, we sometimes switch back and forth between the “modes” of English. Business is largely French in origin; science has a lot of Latin, and domestic matters Teutonic. We don’t know we’re “shifting languages” if we switch from talking about finance to talking about football or the kids, but we are.