Hello. I have experience teaching English to Brazilians (grown up) but a friend recently asked me to teach her 5 year old son. He speaks Portuguese and German, but only knows a few words in English. She specifically asked me not to let him know I also speak Portuguese and German, but I don't think he understands me at all when I speak only in English to him. I feel he is not interest in learning. What should I do? Is there a better way for me to get through to him? Should I speak to him in another language?