Don’t expect the parents to help you!
So I made lists of important, useful phrases and would spend entire classes drilling them into their memories. I’d have each child take turns roll playing and reciting the phrase. Then I would test them at the beginning of each class, (pantomiming drinking water, for example, in order to elicit “water please”). Some example phrases were “Toilet please”, “Water please”, “Sit down”, “Ouch!” “Stop”, “Don’t touch”, “Don’t do that!” “Don’t move”, “Be careful”, “Listen!” “Open/Close” “Where is your….(book? pencil? bag?)” Etc.
I found that, more than anything else, this helped in establishing my authority. It provided rules and order and much needed safety.
The Point System! This is an old standby…and it works. Assign a number of points to each student (write them next to their name on the board). Every time they misbehave, erase a point. I usually do this with the “no Japanese rule”, so that anytime I hear Japanese, I erase a point. This usually greatly decreases the number of fights and disagreements for the simple reason that they don’t have the language ability to insult one another in English.