[pessimizer]

> What I suggest to all my German-speaking/English-preferring friends and colleagues, is to CORRECT the German, in a friendly way, and speak friendlier German while I'm "getting the marbles out" ..

I've heard something different to this and I have to say that it helps in my language learning. You shouldn't correct someone who gets the language wrong, but accept anything that you understand as correct enough. If there is some possible confusion in the meaning, however, you should ask for clarification (e.g. "do you mean you're going to the movies now, or that you went to the movies yesterday?") The language learner will follow up with a different phrasing and/or with questions about grammar that will teach them more than a quickly forgotten correction.