Learning about Vietnamese every chance I get

While in Việt Nam, I am trying to learn more about Vietnamese. It is a complex language with 6 tones (thanh) and different pronunciations of consonants depending on the region of Vietnam. For example, the letter "d"  is pronounced as /j/ in the south and /z/ in the north.
Some of the people I am learning from include:

• Dr Ly Kha, the linguistics lecturer from Ho Chi Minh University of Education and Training.
• Ms Xuan, a new graduate speech therapist who has been my co-teacher and interpreter for the two weeks.
• Dr Alison Winkworth (from Charles Sturt University) who is a director of the Trinh Foundation, and is in Vietnam for one month. Each day she attends language classes and then tells me about what she has learned that day.
• Mr Truc, our Vietnamese guide on the Mekong River - who happily chatted about the International Phonetic Alphabet (IPA) that he had learned to enhance his pronunciation of French and English.

Mr Truc - our guide on the Mekong River who uses the IPA