In graduate school I took a couple semesters of an indigenous American language,
taught by a native speaker of the language. This was her first year teaching and
I don't believe she had more education than a bachelor's degree, and
maybe not even that. The department provided her with a very technical textbook
and an open invitation for help if she wanted it and set her loose on her class.
Unsure of what to do, she spent the first month of class teaching and reviewing
the language's alphabet (which happens to be the Latin alphabet with a
handful of accented letters). Things kind of went downhill from there, and that
year ended up being her only year teaching. I'm certain she could have been
an excellent teacher with some training and guidance, particularly during the
first two weeks of class. The lesson I took away from that situation was that if
you're going to give someone a job, you need to give them the support they
need to succeed in that job.