Don't just pardon my French, please correct it!

Early in my work with our association secretary, I asked her to help me by improving my French by noting my misspeaks and telling me how to correct them. I repeated the request quite a number of times over the first months until, finally when she had me alone in her car she mentioned a couple of of my faux mots. Some months later, she actually interrupted a sentence or two right in the flow of conversation with suggested improvements. Still this would only happen privately. 

Finally, she encouraged me to tutoier. That meant a real effort of distinction that is not a part of my mental structure, since thou disappeared from English (except in prayer books) long before I first saw the light of day. We anglophones are formal with everybody, but totally unconscious of it. Now the challenge is to know when and in front of whom to do it. This bit of linguistic education is now entering into its seventh year with no end in sight!