Writing system

The modern and official Vietnamese writing system is based on the Latin script.

The alphabet

The Vietnamese alphabet, based on the Latin alphabet with some modifications, consists of 29 letters in total.

Aa	Ăă	Ââ	Bb	Cc	Dd
Đđ	Ee	Êê	Gg	Hh	Ii
Kk	Ll	Mm	Nn	Oo	Ôô
Ơơ	Pp	Qq	Rr	Ss	Tt
Uu	Ưư	Vv	Xx	Yy

Diacritics

There are three types of diacritics used in the writing system:

1. Tone marks: Except for the first tone — ngang tone — which requires no tone marks, each of the other five is represented by one of the following tone marks:
   • hook above — second tone — hỏi
   • acute accent — third tone — sắc
   • grave accent — fourth tone — huyền
   • tilde — fifth tone — ngã
   • dot below — sixth tone — nặng.
2. Vowel marks: There are three vowel marks denoting six additional vowel letters beside those in the basic Latin alphabet (a, e, i, o, u and y):
   • circumflex — â, ê, ô
   • horn — ơ, ư
   • breve — ă.
3. The bar, which denotes the consonant đ.

Digraphs and trigraphs

Apart from the individual letters, there are also digraphs and trigraphs, which include:

• Nine consonant digraphs, which represent nine consonants: ch, gh, gi, kh, ng, nh, ph, th, tr
• Eight vowel digraphs, which represent three diphthongs: ia, ya, iê, yê, ưa, ươ, ua, uô
• Only one trigraph, which represents a consonant: ngh.

The spelling rules

The spelling rules, as the name suggests, govern how a specific sound is written under a specific situation.

To understand the spelling rules, you should have a basic grasp of the syllable structure.

The rules are as follows:

1. The initial consonant /k/ is written:
   • q if the medial is /w/ (written u), e.g. quét, quyển, quạ
   • k if followed by e, ê, i or y, e.g. keo, kế, kịp
   • c otherwise, e.g. cá, cửa, cũng
2. The initial consonant /ɣ/ is written:
   • gh if followed by e, ê, i or y, e.g. ghép, ghê, ghim
   • g otherwise, e.g. gan, gừng, gội
3. The initial consonant /ŋ/ is written:
   • ngh if followed by e, ê, i or y, e.g. nghén, nghề, nghiêng
   • ng otherwise, e.g. ngăm, ngỡ, ngò
4. The initial consonant /z/ (soft g) is written:
   • g if followed by i, e.g. gì, giếng
   • gi otherwise, e.g. già, giật, giun
5. The medial /w/ is written:
   • o if followed by e, a or ă, and not preceded by q, e.g. khoẻ, oan, ngoặt
   • u otherwise, e.g. nhuệ, khuynh, quen, quang, quắt
6. The main vowel /i/ is written:
   • i if medial absent but initial consonant or final consonant present, e.g. in, vì, tím
   • y if medial /w/ present, e.g. uỷ, uýnh, nguy, huýt
   • i or y based on precedent if standing alone. As a rule of thumb:
     • y if Sino-Vietnamese, e.g. y 醫 (“medicine”), ý 意 (“idea”), ỷ 倚 (“to rely”)
     • i otherwise, e.g. ì (“inert”), ị (“to poop”), âm ỉ (“lingering”), ầm ĩ (“noisy”)
7. The main vowel /iə/ is written:
   • ia if final consonant absent and medial absent, e.g. phía, lìa
   • ya if final consonant absent but medial /w/ present, e.g. khuya
   • iê if final consonant present and initial consonant present but medial absent, e.g. biến, kiểu, tiếp
   • yê if final consonant present but initial consonant absent and medial absent, e.g. yếm, yết
   • yê if final consonant present and medial /w/ present, e.g. uyển, quyết
8. The main vowel /ɨə/ is written:
   • ưa if final consonant absent, e.g. mưa, nhựa
   • ươ if final consonant present, e.g. bước, rượu, vườn
9. The main vowel /uə/ is written:
   • ua if final consonant absent, e.g. múa, chua
   • uô if final consonant present, e.g. muộn, cuối, thuốc

Since the writing system were originally developed by Portuguese missionaries, it is reasonable that some of these rules bear a strong resemblance to those of the writing systems of European languages: c/k/q in English (court, king, queen), gh and gi in Italian, etc.

Placement of tone marks

Tone mark placement is as follows:

• If the vowel is a monophthong, which is represented by an individual letter, place the tone mark at the letter.
• If the vowel is a diphthong, which is represented by a digraph, then:
  • If the second letter is a, place the tone mark at the first letter.
  • Otherwise, place the tone mark at the second letter.

The rime table provides the correct tone mark placement for each rime.

Irregularies, ambiguities and variants

After hundreds of years of development, irregularities are expected, if not inevitable.

Rime with irregular spelling

Rimes with irregular spelling include:

• a + /w/ written ao (regular: au)
• ă + /w/ written au (regular: ău)
• ă + /j/ written ay (regular: ăi)

The rime table provides a comprehensive overview of such rimes.

Alternative placement of tone marks

The three rimes oa, oe and uy carry the medial /w/, represented by u or o, and monophthongs as the main vowels, represented by a, e and y, respectively. According to the spelling rules, tone marks should be placed at the letter representing the main vowel, e.g. hoà, khoẻ, thuý.

However, there is the old-styled tone mark placement, which has tone marks placed at the letter representing the medial, e.g. hòa, khỏe, thúy (except for the words starting with q).

The dispute between i and y

For many words, specifically the Sino-Vietnamese words which start with one of the following consonants: h, k, l, m, s, t, and have /i/ as the whole rime (both medial and final consonant absent), there exist two possible spellings:

• Standard: uses i.
• Non-standard: uses y.

Examples:

• hi vọng & hy vọng — 希望
• kỉ luật & kỷ luật — 紀律
• lí do & lý do — 理由
• mĩ thuật & mỹ thuật — 美術
• thạc sĩ & thạc sỹ — 碩士
• công ti & công ty — 公司

What makes things complicated is that, for many of those, the non-standard form is actually preferred over the standard (mostly due to aesthetics and/or tradition).

The spelling of quốc

The syllable/word/morpheme quốc, borrowed from Chinese 國 (“state”, “country”), is an exception of not only the writing system but also the whole language. Theoretically, such a syllable violates the phonotactics of Vietnamese: qu indicates that the medial /w/ is present, whereas ô is a rounded vowel. The two of them are not allowed to co-exist in Vietnamese.

The spelling is a mistake caused by its unusual pronunciation, which is:

• like cuốc in the Northern dialect.
• like quấc in the Southern dialect.

Which one is correct? Short answer: quấc (the reason is out of the scope of this article). The thing is probably that, at some point in history, the people in the North started to pronounce it like cuốc (the reason is also out of the scope of this article), which results in the unusual spelling quốc.

After all, why did we settle for quốc as the standard spelling? We don’t know for sure, but perhaps it was intended to serve as a middle ground between the dialects. Eventually, what was originally a (rather unaware) mistake ended up being the “correct” form.

The soft g sound

As governed by the spelling rules, g before i indicates the soft g sound (/z/). This rule draws inspiration from the Italian writing system, in which g also indicates the soft g sound when preceding e or i. This poses a question: what sound does g before e or ê make in Vietnamese? Logically, it can’t be the hard g sound since we have gh for that purpose, so it must be the soft g sound. However, one of the unspoken rules of the Vietnamese writing system is that placing g directly before e and ê is essentially forbidden, as seen in giẻ, gieo or gièm pha. For the sake of comparison, in Italian, both ge and gie (sometimes pronounced the same) exist and are in common use.

It is all fine until you realize the vowel /iə/ can be represented by ia or iê. What happens when g precedes either of them?

Theoretically, the sequence giê can mean two different things:

• Soft g sound + vowel ê
• Soft g sound + vowel iê

Fortunately, the language resolves within itself on this one: it is almost always the second possibility. The first happens very rarely (if ever).

Similarly, the sequence gia can also mean two different things:

• Soft g sound + vowel a
• Soft g sound + vowel ia

Again, the language sorts itself out: it is almost always the first possibility. The second happens very rarely, but there is one exception: the word/morpheme gịa, as in giặt gịa. However, in this case, there are no ambiguities since the tone mark placement, as governed by the spelling rules, clearly points to the second possibility because if it were the first, the tone mark should be placed at the vowel a, which would produce giạ instead of gịa. Nonetheless, this word is regional and very uncommon (in fact, the author even needed to look up the dictionary for an exception).