External student as well. Son going to Sec 1 in Sep 2018.
Using Mandarin during the assembly for the bridging course was indeed very odd... Will be a concern if this is a policy now (!!!) and may need to make contact with school management for clarification if this continues :)
好怪, 兩個極端 - 香港EMI學校 - Medium of Instruction 不單不是英文, 仲要非母語 (何解?)