Right on, Yingwen! What a great reply! It really seems that way some times, that we have to jump through all the hoops to make an impression.
But it seems to me, if they're adult learners, its more about getting them to express themselves in English, and less about us having them listen to us.
Maybe having the students practice negotiations, debate, arguement and speech-givin--all the things they can already do in their native language, but haven't had any experience with in English--seem pretty pointless if we're just there to entertain them.
Maybe the first meeting with each new group we could clue them in on the idea that classes with foreign teachers may be a bit different than customary, that we expect participation on their part during the classes, that their grade, promotion, employee evaluation, success in getting that job with the foreign company depends, at least in part, on their ability to take part. That their ability later on down the road to take part as a manager in a foreign company rather than just sit and watch in meetings, depends alot on the practice they get in the classes they get with us.
We're not just teaching language, but the ability to communicate.