Congrats on going to Korea. That's the best place for TEFL teachers, in my humble, aggravated opinion. I don't mean to sound negative, but I teach in a certain country down in SE Asia--a place that will aggravate the hell out of the best of us.

Anyway, my advice to you runs parallel to Dr. Z's advice--introduce pronouns early, especially non-to-pronoun conversions. I have students here who've been going to English classes for over nine years, and they STILL don't know pronouns, man. Cheating has worked well for them GPA-wise, even though they still don't know the difference between 'me', 'my', and 'mine'.

Good luck.

SiamSap