The ethnic minorities in Vietnam that don't natively speak Vietnamese speak a large number of languages natively, but most of these people also learn Vietnamese, making it the primarily language of communication across ethnic groups. Along the borders, Chinese and Khmer are also commonly spoken native languages. In the past French was a common foreign language learned in the country, but this is slowly shifting to English and many workers in the tourist industries speak one or both of these languages.
Religion
Vietnam is one of the most atheist countries in the world as over 80% of the people claim to be atheists. Among the last 20% of the population, about half are Buddhist and the last half consist of various groups, with Roman Catholicism being the largest of these.
Buddhism is a religion or philosophy that encourages people to strive for enlightenment. Adherents believe that each being is reborn until enlightenment is reached, at which time they escape the cycle of birth and death. To accomplish this, every being must speak, act, and live in a positive manner; this is magnified with the force of karma, which dictates an individual's later life and/or their rebirth.