On Tuesdays, in addition to the regular credit class that I teach, I also teach 5 OT classes. These are smaller classes of about 10 students who sign-up for extra English. The classes are 45-50 minutes long and I have to cover 2-3 pages of the "Smart Choice" Textbook.
My style of teaching is totally interactive. I will NEVER stand up at the front of the class and lecture with the exceptions of the first day syllabus explanation and when I talk about the tests or homework assignments. Even with the grammar lessons, I will always leave lots of gaps on the board and work together with their students to get them to help me fill it in. And I will ALWAYS do an example of what I expect for when I set up a conversation activity. In this instance, the students usually have to ask me 3-4 who/what/when/why/where/how questions beyond the initial question (such as, "What's your favorite movie?")
The first 4 classes on Tuesday seem to love this style. They are all participating, giving me some answers and feedback. And the class just works, with everyone seeming to be happy and not sleeping and learning something. However, the last class is a nightmare. Dead silence. It's a perfect storm of quiet, low-level, unmotivated students with not a single bright light mixed in. I soldiered on with my normal style for a couple classes but yesterday, I switched it up. I went into Robo-Teacher mode. No interaction, just lecture, kind of like the standard Korean style. I would ask my normal questions but then just answer them myself. Leave the blanks on the board but just fill them in myself. Then I handed out worksheets based on the lecture. And they seemed to love it. Like all smiles and thank-you's at the end of class. Back into their comfort zone of what they've had their whole lives.
Anyway, what I'm saying is this: do whatever it takes. If you have a "dead-class" don't stress yourself out trying to force interaction. It's just not worth it. Just lecture, as per the standard Korean way. I know it's not ideal for actually learning, but it's only the second time I've had to do it in over 4 years at my uni, so my track record for interactive is still intact.