I've decided there is a possible positive to some Vietnamese not understanding their own language; perhaps those that don't understand Foreigner Vietnamese have an intellectual weakness not normally detected in our sometimes limited interaction. Just a thought; if they don't "throw the switch" what does that tell us about the person? Anybody care to hypothesize?
Yesterday I went into a small shop selling cases of pop and beer; the woman waiting on me would be late forties early fifties. I asked for a small case of bottled Coca Cola and she then pulled a case out that had two bottles already removed, She said she would get two more to fill the case, I said don't bother that is fine the way it is. In the conversation (in Vietnamese) there was not one repetition, not one misunderstanding. I looked into the women's eyes and saw intelligence and awareness. The woman was poor and not well educated and spoke no English. I left the shop with two Cokes short of a full load. Viet Kieu won't understand the abuse of an idiom, but anyway I felt more confident with my Vietnamese and am happy I found somebody who could "throw the switch" effortlessly.