About Vietnamese
Vietnamese is the national and official language of Vietnam. It is the mother tongue of 86% of Vietnam's population, and of about three million overseas Vietnamese.

It is also spoken as a second language by many ethnic minorities of Vietnam. It is part of the Austroasiatic language family, of which it has the most speakers by a significant margin (several times larger than the other Austroasiatic languages put together).

As with Korean and Japanese, much vocabulary has been borrowed from Chinese, most notably Cantonese, especially words that denote abstract ideas (in the same way European languages borrow from Latin and Greek), and it was formerly written using the Chinese writing system, albeit in a modified format and was given vernacular pronunciation.

source: Wikipedia