France started by sending missionaries to Vietnam and in 1887, France made Indochina a French colony. Vietnam declared independence in 1954.
Colonization in the nineteenth century answers the "how" and "when" of Vietnam becoming French-speaking. The French arrived in southern Vietnam because of the counter-weights to British presence in East, South, and Southeast Asia and the earnings which could be had from plantation economies. The colonialists simultaneously established a countrywide system of educational and governmental facilities which quickly turned the Vietnamese peoples into bilingual speakers of French and Vietnamese.
England isn't a french speaking country...
There are no French-speaking countries in Asia. French-speaking countries are primarily located in Europe, Africa, and the Americas.
France, Belgium, Switzerland, Algeria, Senegal, Madagascar, Canada, and Vietnam
Vietnam was formerly French Indochina, a French colony.
Vietnam
Laos is a country in Asia where French is spoken as a second language due to its history of French colonization. It is one of the few Asian countries where French has official status alongside Lao.
Quebec in Canada, some islands in the Carribeans (Haiti), France and French Guyana, Monaco, Belgium, Switzerland, Andorra, Polynesia Then you have a lots of countries with a French-speaking minority like Cambodia, Laos, Vietnam, Louisiana in the United States, etc...
Louisiana became French-speaking due to its colonization by the French in the early 18th century. The French influence in Louisiana was further perpetuated by the Louisiana Purchase in 1803, which brought more French-speaking settlers to the region. Over time, French language and culture became ingrained in the state's identity.
French Indochina War, aka 1st Indochina War (1946-1954).
Quebec in Canada, some islands in the Carribeans (Haiti), France and French Guyana, Monaco, Belgium, Switzerland, Andorra, Polynesia Then you have a lots of countries with a French-speaking minority like Cambodia, Laos, Vietnam, Louisiana in the United States, etc...
Some French-speaking Asian countries include Vietnam, Laos, Cambodia, and parts of India (such as Puducherry). French is considered one of the official or administrative languages in these countries due to historical colonial ties with France.