Imagine looking at that through their eyes- two words using an unfamiliar alphabet mysteriously become one and one symbol is replaced by an apostophe, yet they're the same. Also, there may be differences in the pronoun system and the way they are used, so the underlying concepts may be trickier than they seem. There may, for instance be different forms of you or cultural issues about using the word- in some cultures using you when speaking to a teacher might be considered overfamiliar. Can you check what system there is in Korean? Also, build on what they can use- if they're OK with happy, add other adjectives, then move them on to 'I'm happy' a bit later.Even after saying the words "I am," and "I'm"