The Spoken Language:
Due to its unique geographical location, and due to its years of interaction with foreign occupation, the Vietnamese spoken language has seen many influences and changes.
The native Vietnamese spoken language is often called Nôm. (There is also a writing system, based on Hán-Tự (classical Chinese), called Nôm.) Nôm the spoken language can be written in either Hán-Tự, or in the written language Nôm, or in a Romanized script called Quốc-Ngữ. (This is similar to the way a Japanese sound could be written: "Honda" is a Romaji (Latin) version of a Japanese word that can also be written in Hán or Kana.)
Years of Chinese occupation brought about a large subset of the spoken language called Hán-Việt, which is Vietnamese pronunciation (non-native pronunciation) of Hán characters. (Remember, Hán-Việt is a spoken language, a way to pronounce Hán; it can be written in either Hán-Tự or Quốc-Ngữ.) The Hán-Việt sounds are similar in tonality to the Cantonese spoken language (to the north). For example, the Hán word "吃" ("eat") has a Cantonese pronunciation of "sực" that is similar to the Hán-Việt pronunciation of "thực". The corresponding Nôm pronunciation is "ăn". Vocabulary-wise, about 60-70% the Vietnamese vocabulary has its root in the Chinese language. Since it is a way to pronounce Hán, Hán-Việt has a one-to-one correspondence to Hán vocabulary. For example, the Hán word "日" ("Day") corresponds to the Hán-Việt pronunciation of "Nhật" which is pronounced "Ngày" in native Vietnamese.
Besides its similarity to the Cantonese spoken language to the north, the southern Vietnamese accent is similar in tonality to the Cambodian and Thai spoken languages to the west.
Years of French occupation also introduced many French nouns, like "cà-phê" ("cafe"). American influence introduced words like "xưng gum" ("chewing gum").
The Written Language:
There are three versions of the Vietnamese written language: Hán (Chinese), Nôm, and Quốc-Ngữ.
"My mother usually eats vegetarian at the temple every Sunday."
The characters in green are Hán-Tự.
The characters in orange are Nôm.
The words in blue are Quốc-Ngữ.
1) Hán-Tự (Classical Chinese): Up to the late 19th century, all court documents and official transactions were written in Hán-Tự. For many centuries, a large portion of the Vietnamese spoken language was Hán-Việt which was written in Hán-Tự. Each Hán character would have a Hán-Việt pronunciation and a Nôm pronunciation. For example, the Hán word "本" ("root", "principle") can be pronounced as either "bản" in Hán-Việt or "vốn" in Nôm. For the Vietnamese people, only the privileged few were able to learn and master this difficult written language.
2) Nôm: As the Vietnamese spoken language evolved, a new system of writing was invented around the 8th century, called Nôm, which was based on Hán characters, which looked like Hán characters, but did not belong to the Hán vocabulary. (It is much like the way the Japanese Kana and the Korean Hanja were developed, based on Hán-Tự.) (For example, in the Figure above, the Nôm word for "mother" has the native Vietnamese pronunciation of "mẹ"; it looks like a Hán character but does not belong to the Hán vocabulary, ie, a Chinese reader would not understand that word.) This new writing system was not used in official documents but in popular literature, most notably by Nguyễn Trãi in the 15th century, and by Nguyễn Du and Hồ Xuân Hương in the 18th century. In 1867, Nguyễn Trường Tộ proposed a system of Nôm called Quốc âm Hán tự ("Han characters with national pronunciation") along with the abolition of Hán as the court language, but the new system was rejected by Emperor Tự Đức. Like Hán-Tự, Nôm was difficult to learn and to master.
3) Quốc-Ngữ: In the 17th century, Christian missionaries and European traders came to Viet-Nam. A Romanized version of the written language (later called "Quốc-Ngữ", which is Hán-Việt for "the national language") was invented to facilitate trade and Christian conversion. (Father Alexandre de Rhodes, a French-Portuguese Jesuit missionary, wrote the first Portuguese-Latin-Vietnamese dictionary which was eventually used by scholars to create this new Romanized writing system.) Quốc-Ngữ, based on the Latin alphabet, is basically a phonetic script, with almost no exception to the established rules of pronunciation. (The only known exception is the pronunciation of the word "Quốc" itself.) It has been said that, if one already knows how to speak Vietnamese, one can learn to read Quốc-Ngữ in two weeks or shorter; that's the length of time of an adult education class to teach illiterate Vietnamese adults (who already know how to speak Vietnamese) to read. Many Vietnamese then were able to learn and to master this written language. Today, Vietnamese people are among the most literate in the world, with the literacy rate of over 80%, rivaling many Western countries'.
In the late 19th century, when France colonized Viet-Nam, Hán-Tự was abolished as the official writing language. At the beginning of the 20th century, the use of Nôm declined quickly as Quốc-Ngữ became widely used. Toward the late 20th century, Nôm almost died away, with only a few scholars being able to read and write Nôm; that meant many notable works of literature that were written in Nôm would have been "lost." With recent development of computer software, however, one can again write Nôm by inputting the Quốc-Ngữ equivalence.
