Teachers and students would be pretty tired in full immersion classes when the students know little Mandarin. , because students are required to pay attention to every word the teacher says. If it's only gonna be 1 hour of full immersion per day, i think that's fine, but more than 2 hours for beginners, OMG... Teachers vice versa. They have to be well-prepared. If one teacher has more than 6 or 7 hours of immersion class pre day, OMG..

It should depend on the capacity of the teacher to handle it and of course we should make priority on how much the students can handle it. They are the ones that will be grasping and comprehending everything that teacher is saying. So, therefore using English should be taken slowly and be dependent on how the students will take it particularly if you are handling the beginners. That is one example of what we call language barrier. But soon, they will be handle more of it later on.

I have many years of experience teaching young children in immersion programs, the best time to use English is during an emergency, for example, when the child fell down and hurt her knees, when she fell sick and wanted mommy, or when she had a serious fight with her friends..of course, during a real emergency of earthquake or fire drill, they only respond to English.

Although the teacher should not speak English in class, she/he should let children express themselves in English. Otherwise, if the child could not speak the language that you are teaching, he/she is going to create behavior problems.

Frankly speaking, most of the Chinese immersion programs in Bay Area, CA have difficult time to set up a true immersion environment because most students are English native speakers. If you have at least 1/3 to 1/2 of children who are Chinese native speakers or heritage speakers, the whole class' will be fluent in a year. Otherwise, it is 15 children immerse with one teacher. It is not very realistic.

I agree AntonyP's saying that we should make priority on how much the students can handle it. But is not true at the beginning of immersion class, the teacher has to set up some forceful rule to encourage students to speak target language only?

Maycliu, I am also very interested in Chinese native speakers and heritage students' role in the immersion Chinese class. It is possible for teachers to explain everything (100%) by Chinese language and body/action language to the very beginners without any Chinese language backgrounds?