My grade ones at the boys' school are so behind it shocks me.

So, I have a three grade one classes at the boys' school.
One is about where the grade ones are at the girls' school are, which I believe is still behind where students are expected to be by that point. They're advanced enough though that they usually understand my instructions, and are able to interact with me in and out of the classroom.
My second grade one class, however, is so behind that it actually hurts me. I do not know what to do. Every week, I come to class with something more basic to try to get them participating, and each week I talk over their heads. I'm really not sure what to do. It looks like I will have to give up on teaching conversation and actually go back to teaching phonics, the alphabet and vocabulary. Really, teaching vocabulary is not what I am here to do! I am supposed to be teaching conversation, which means I only explain vocabulary as it comes up!
But, unfortunately, my students can not converse. At all. So I am teaching vocab. Which is fine, it can still be a lot of fun, because vocab can be easily turned into a game. Easy, but not very interesting for me, and definitely not too interesting for students.
Today was a memory game, where there were twenty-five numbered squares on the board, with each square correponding to a question or answer. Students get to choose two at a time, to see what question or answer they are, and then they try to match them up. Last week we covered opposites (which was WAY beyond even my second class), so many of the questions were on opposites (What is the opposite of up? Down) and other topics I've covered, like clothes and body parts.
The first grade one class got it wonderfully, which filled me with confidence. The second grade one class answered, occasionally got points, but it was clear 90% of the time that they had no idea what was going on. These kids have been studying english for seven years and they don't know the words "opposite", "what" and "top" until I come? And yet they can perfectly pronounce "I'm fine thank you, how are you?" That is only used once, and they would be just as well off to say fine, or good, and not have a programmed sentence pounded into them!
I don't know what to do. It's not fair to most of them to keep teaching what I am teaching, but without speaking to Korean to them in the classroom, I'm not sure how I can make it any easier. I'm thinking that next week I'm going to do the same game but with rhyming words, or maybe just classic memory with just pairs, no linkages.
Anyways, I'm struggling with this one class. The last grade one class is pretty behind too, and I have to rely on the coteacher, because the kids don't even understand "Open your books".
Oh well, tomorrow I have the other awesome grade two class and the grade threes. The guy that drives me crazy and his hair-style impaired friend have been in the office getting yelled at every day that I have been here for the past week. I'm pretty sure that they both probably failed all of their high-school entrance exams. It's too bad, but they really don't try. It's also too bad that they're in Korea, because no-one here will care.