Addressing people in Vietnamese is much more difficult than in English. However it also has its advantages like by the way addressing people correctly, you can show much respects to people that you are talking to. Also, while seeing people addressing to others you can know exactly there relationships, range ages, positions in family, society, .... For details how to address people in both Northern and Southern Vietnamese, you should read the following articles then finish the exercises: http://www.howtospeakvietnamese.com/how-to-address-people-in-vietnamese/ Hope you find it helpful !