For me, my (half) Asian heritage and near-native fluency in Cantonese actually helped me get a teaching job in Hong Kong fresh out of college while I was still in the midst of an online TEFL course. However, once I started, I discovered that my job preferred for me to hide my heritage in front of students.
My boss was definitely pleased with my language abilities since it helped during meetings, but if I revealed this secret ability to my students, then they would inevitably get lazy and start falling back on our shared language — so she requested that I feign ignorance during classes (which is actually a pretty common request from language schools since they want to emulate complete immersion as best as possible.)
I was able to do this because my mixed looks gave me enough ambiguity that I could pass for either full white or at least having been so Americanized that I might never have learned my mother’s native tongue. None of the students suspected that I was anything other than a gui mui, a foreign white girl, and they would be forced to struggle along in English even in the face of confusion and misunderstanding. Or at least, this was how I approached the job at first.
It was not until after I had been teaching for three to six months that I began to slowly reveal my hidden power. It began at first as a way to talk to parents whose English skills were not the best. I would send my students to another room while I hurriedly conferenced with their parents in Cantonese. Then I began to reprimand students who would use cuss words or derogatory slang. They assumed I would not understand and so felt free to make inappropriate jokes with impunity.
At first I had employed the tactic of no foreign language in the class as a means to stop their rude behavior while not showing my understanding. Then I finally cracked and spoke to them about how disrespectfully they had been treating me. You should have seen how their mouths dropped open. And yes, they ceased their rudeness after they realized that I could relay to their parents exactly what they had been saying.
Finally, I began to use Cantonese in my high school classes to explain complex ideas and concepts. These older students understood the necessity of picking up English while appreciating that I could express deeper meanings in a way that they could understand. I did this sparingly and only when I could not find a synonym in English that they knew.”