I have experienced a bad teacher, let me give you an idea of what it was like.
Ok, so the subject was Spanish I, not so bad. I was enjoying my teacher, because she taught us well enough so that the subject came naturally to us. only about 5 weeks into school, my ENTIRE CLASS was transferred to a different teacher, with no say in the matter. I really didn't understand why this was necessary, but whatever, maybe the new teacher wouldn't be so bad (ROFLCOPTER).
The new teacher hardly went over some material, focused on stuff that we weren't supposed to focus on yet (because we weren't at that point in the book), gave us quizzes a LOT more frequently, and quizzed us on stuff that she didn't go over. We never even had reviews before tests. At one point, she started giving us sheets to study from for the upcoming quizzes, and said to study those sheets because that's what we'd be quizzed on. Quiz comes, aaaaaannd bullshit. I studied the fucking papers every time before the quizzes, and there was shit on them every time that we didn't go over in class, and said shit wasn't even on the fucking study papers.
At that point I was fucking pissed. I could easily see my grades slipping in the class, and there was nothing I could fucking do to improve said grade, because I was studying as much as possible, and that didn't even help. I had 100% in everything with my first teacher, and I got B's on damn near every paper with the second one. Hell, on the quizzes, we got marked down for being textbook-perfect because that was "not what she wanted to see" on our quizzes.
"How could this happen?" I wondered, and then I looked back a bit more on how she taught us. Whenever we were doing activities in the textbook, and we came across a word that we didn't know, she told us to look the fucking words up ourselves. Yes, this teacher used the "let's throw everybody in the water, and at least one or two of these fuckers will find out how to keep themselves alive so we can work those poor bastards harder than ever" method. The scary part of the class was seeing everybody else around me who also got 100% on everything with the previous teachers get scores like 4/17 or 10/17 typically on quizzes and activities 'most every day.
Now, I didn't really hate the teacher, because she was a nice person and all, but I was pissed at the fact that I wasn't doing well in the class, because getting straight A's or not was the defining element on whether I got to see a Christmas that year or not. Hopefully that helps give you an idea.
Show Capcom we want an X9!