In reply to Turnoi.

I would not criticize the people doing that but the system that allows virtually anyone even with a low educational profile (that is, without a degree in a language-related subject matter plus decent professional teacher training on top of that) to become "teachers" and not teachers.

This is a bit of a tangent from the original post, but, I disagree with the idea that only those who specifically majored in an English-related subject are qualified to teach English. Someone with a masters in history or philosophy, for example, will have had to write countless academic papers and with a good teaching program in addition should be well able to teach Oral English and culture classes. It's not uncommon for non-English majors to have superior English to those who studied English specifically. If you are talking about someone teaching a really academic subject like linguistics, than of course I agree that they should have the appropriate background. But any educated native speaker is already an expert at spoken English. The real question is can he or she teach it, and a degree in English may not be an advantage over something like theater or sociology…

In some extreme cases, this would have the effect that there are native speaker "teachers" in China who cant distinguish "its" and "it's" properly in their written English or 18-20 year old high-school graduates who teach things like "gonna" to their students.

I often make "its" and "it's" typos myself. I know you can't use "it's" as a possessive (even if that's a fairly logical mistake to make), but I still will type it that way, just as I'll even mix up there, their and they're when typing. I usually find these errors if I do an edit. My point is that such a small error is inconsequential. I'd hardly see that sort of thing as an "extreme case" of a bad or unqualified teacher. The extreme case would be the predatory teacher who doesn't plan lessons and doesn't give a $hit about the students.

As for the thing about someone teaching "gonna'", do you mean as "correct English" and not deliberately to familiarize students with the way English is actually spoken colloquially? It makes sense to teach students some of the most common colloquialisms if they are going to be in any situation where their listening to native speakers is important. Teaching "gonna" as correct written English is insane.

Finally, what makes a good English teacher, or any kind of teacher, isn't just the expertise in the relevant discipline, but also the ability to impart it to others, to engage others and make the subject interesting…