I have been living here in Vietnam for a little over 3 months, the Vietnamese language is very complex, lots of inflections, and the North, Middle, and south all have different ways of saying things, so if you say it right in one place, someone from another place may look at you like your crazy. Hahahha

But everyone here is very nice and I have only had my motorbike helmet swiped one time. A local friend gave me a new one. So, I think you can get by in the city's with no Vietnmenase... in the more rural areas.. HAHAHA not so much.