I know a lot of foreigners who speak very good Japanese...and they usually end up speaking too much of it in class...not good for the students. They come to class to speak English...remember that, and I mean speak it, not listen to the sensei blab until the hour is over. I like to just wind em up and sit back and listen , correcting the same mistakes over and over again...but I`m not complaining `cus it keeps me employed. The students will be too shy to say if they don`t like lessons...they will let the teacher know by not coming back. When I took the Berlitz training, they stated that they do not allow any language save the target language in class...and that includes ne, so desu, hai, shinjilatnai etc etc...zero Japanese and thats what I do...I do not allow them to speak their mother tongue from the moment they enter the school let alone in my class. I only get them for an hour or two a week and I know very very few actually speak, read or listen English outside class so they remain at the same level. I highly recommend you do not show off your fluent Japanese in school...save it for the Izakaiya after class.
