Oh, I feel your pain. I taught 6th grade in an elementary school last year only one day a week but it was a Thursday so I used to dread that day throughout the week. I found the students were either rude or would simply stare blankly at me when I said anything.

I'm teaching some 6th graders this year too but in a hagwon and I have less problems with that grade more than others. They can be tired but the smaller class seems to suit them better. My thinking is that hormones probably start to play a part too, they become very self-conscious at that age so, in a big class, they don't want to look stupid while others get cocky at that age and act out accordingly.

I don't want to just complain (although hopefully you can see it isn't just you, it's a difficult age to teach). Practically speaking, I used to have a list of all the students names and I would make sure to ask questions to each and every student systematically so I didn't miss anyone and everyone knew they could be asked at anytime. (That would be maybe four or five questions a day). I felt it was a good idea to call their names because I think it helps with respect, I don't know about your school but my school used to just tell me to call their class number.

I also had a laminated board with student's numbers on so in class I could give points to students who participated and then gave them candy or something at the end. Of course there will be students who simply don't care but some students in the middle will start participating more hopefully. Of course, you also have to be careful that you don't give points to the same good student every time or everyone will give up. Try to ask different students questions and keep it somewhat balanced.

Hope that helps a bit but really I think the best thing is to not get stressed (as difficult as that is) and keep things light, smile and try using smatterings of Korean to help give them the idea. They can't pretend not to understand if you explain key words in Korea.

Best of luck!

I'm in a weird situation where my 6th graders started this year the bright, sunny kids they were in 5th grade, but over time, they're slipping gradually into Zombieland.

One way I've coped is by getting them to do more group activities so they interact with their peers more than teachers. The energy picks up once they're allowed to talk to their friends. (So board games, cards games, etc are good.)

I also give points to teams who answer questions, but if I notice the same 4 kids keep answering, I'll suddenly give bonus points to that team or extra points to an individual student. The hands start waving then~

My students were fantastic as 5th graders, so I'm absolutely positive it's all the fault of hormones. Puberty is rough.......

Based on my experience, I'd have to pass up the hormones and puberty argument as BS.

I teach 6th grade classes at 4 different schools. Every one of them is fantastic, they're just as enthusiastic, fun and respectful as they were last year. At one school, one of the 6th grade classes has been a nightmare though they're slowly making progress. It should come as no surprise that the homeroom teacher was the most vile and loathsome punk you could imagine and should have no business near a school, he's since taken some kind of sabbatical. His damage has been done and it's really tough getting the students back to the way they were last year.

A skilled HR teacher is able to teach the students to be respectful, despite their hormones.

My advice is to start with writing activities. I've had great success with my nightmare 6th grade class by completely cutting out games and making my lessons more "serious". The first lesson, I'll focus on explaining and teaching the sentence structure in detail. I always try and show them the pattern of the key expression. This is followed by a simple writing activity.
Lesson 2 starts with a brief review and a more challenging writing activity. While they're busy, help students one-on-one with whatever they're struggling with.
Lesson 3, I'll do a listening test. I'll usually do 5 easy, 5 medium and 5 difficult questions.