[mesmark]

Well, with groups that age, I first just focus on the vocabulary, "a headache", "a fever", etc.

We might spend a period or two just on the vocabulary. Then I'll add, "He has ..." and "what's wrong?" in on the third period. However, my groups know what "he" and "have/has" mean.

Kids this age will take to some formulaic speech and make use of it, but expecting a group of 30 to all break it down and understand the parts might not happen. Usually, at that age they haven't learned grammar in their L1. Everything needs to be taught very slowly and build. Make sure they understand "he", "I" and have some concept of what "have" might mean, possession/on person - it may even be more abstract or not match up in Korean. In Japanese most of the symptoms "come out". It's not something you "have".

I assume if you're having a lot of troubles, it's because they've been taught a lot of formulas - "How's the weather?" - "It's sunny." But they don't know how to use the parts.