The mutual borrowing between both languages is really amusing when visiting Montreal.

I sat down in a restaurant in the historic part of the city, and the menu was loaded with "apostrophe s" and "le Hamburger". I then looked at my server and said, in plain English, "My high school French teacher used to make fun of this as 'franglais'".

The server then laughed and told me, "oh, we mix English into French here all the time and don't care."

The next day I walked by a youth American football league in a city park.

Even my mother's household, which was Quebec-French speaking in the US, would say "poe-tat" instead of "pomme de terre." ("Potato" with a French accent instead of the literal "apple of the earth" word that I learned in school.)

Nice anecdotes, but the last one is a misinterpretation that got me into a rabbit hole. "poe-tat" is juste "patate" and is widely used not the least because it's just faster to say than "pomme de terre" (following Zipf's law of abbreviation and the principle of least effort). It's more informal, but it's pedigree is excellent as it comes from Taíno via Spanish, was first recorded in 1582 and recorded by the French Academy in 1762… which was actually only the case for "pomme de terre" in 1835! It seems that "pomme de terre" referred to other tubers in the distant past, but that the famous agronomist Parmentier remarketed "patates" as "pommes de terre" in the 18th century to promote their acceptance.