There are six tones, or thanh điệu, in Vietnamese, each can be associated with its pitch contour in a five-level scale.
| Tone | Vietnamese name | Diacritic | Pitch contour |
|---|---|---|---|
| first | thanh ngang | ∅ (a) | mid-high level (44) |
| second | thanh hỏi | hook above (ả) | mid falling-rising (313) |
| third | thanh sắc | acute accent (á) | mid rising (35) |
| fourth | thanh huyền | grave accent (à) | mid-low level (22) |
| fifth | thanh ngã | tilde (ã) | mid level with glottal stop, sudden rising (33ʔ55) |
| sixth | thanh nặng | dot below (ạ) | mid level with glottal stop (33ʔ) |
Coincidentally (or not), the name of each tone in Vietnamese carries that same tone.
Six basic tones
First tone
The first tone starts with mid-high pitch and maintains its level until the end.
Second tone
The second tone starts with middle pitch, then falls to low pitch, and finally rises back to middle pitch.
Third tone
The third tone starts with middle pitch and rises to high pitch.
Fourth tone
The fourth tone starts with mid-low pitch and maintains its level until the end.
In order to acquire the fifth and sixth tones, you first need to learn the glottal stop.
Glottal stop
The glottal stop, denoted by the letter ʔ in IPA, is the sound produced by obstructing airflow in the vocal tract. In layman’s terms, it can be understood as the little pause between the vowel sounds in “uh-oh”, or the sound of the t in “butter” (“bu’er”) pronounced with the Cockney accent.
Fifth tone
The fifth tone starts with middle pitch and maintains its level, followed by the glottal stop, then immediately rises to high pitch right after the glottal stop, and maintains its level until the end.
Sixth tone
The sixth tone starts with middle pitch and maintains its level, followed by the glottal stop. It sounds exactly like the first half of the fifth tone.
The sixth tone, and thereby the syllable that carries it, is normally shorter than the other tones, largely because the glottal stop causes an abrupt stop rather than a follow-through like the other tones.
Out of the six tones, the fifth and sixth tones are the most difficult (fifth is more difficult), and it’s not hard to guess why. They are also often the last to be mastered by native speakers. This is evident in young toddlers who substitute the fifth tone for the third tone before they can pronounce the fifth tone correctly.
All-in-one tone chart
Checked tones
When the final consonant of a syllable is a stop (p, k, c, or ch), the syllable can only carry two tones: the third and sixth tones. When the third or sixth tone appears in such syllables, it’s called a checked tone.
The pronunciations of the checked tones are a bit different from usual. The checked tones are:
- Short (as short as the normal sixth tone and shorter than the other five)
- Level (no rising and no falling)
It’s very logical and natural for the checked tones to have those characteristics. First, they are short because there is a stop consonant at the end, similar to the normal sixth tone (in fact, the glottal stop is, linguistically speaking, also a consonant). Second, they are level because there are only two of them, which means rising and falling in pitch are not really necessary; instead, they are distinguished by the height of the pitch: high and low.
Checked third tone
The checked third tone is high. It starts with high pitch and maintains its level until the end. It sounds exactly like the first tone but one level higher.
Note that the checked third tone doesn’t have a rising pitch like the normal third tone.
Checked sixth tone
The checked sixth tone is low. It starts with mid-low pitch and maintains its level until the end. It sounds exactly like the fourth tone.
Note that the checked sixth tone doesn’t need the glottal stop like the normal sixth tone because there is already a stop consonant (in fact, it would sound awkward to pronounce it with the glottal stop).
Placement of tone marks
The placement of tone marks is decided by the spelling rules.
Tones in dialects
As is the case with pretty much every other language, there are differences between the standard language and how Vietnamese speakers actually pronounce the tones. There are two major dialects in Vietnamese: Northern and Southern.
The Northern dialect
The Northern dialect is formally called phương ngữ Bắc Bộ, colloquially giọng miền Bắc, or giọng Bắc for short.
In general, the Northern dialect (Hanoi) pronounces the tones in the same way as the standard language, but there is one exception: the second tone. In reality, speakers of the Northern dialect do pronounce the second tone like the standard second tone, but only in isolation or careful articulation. In real-life speech, be it formal or informal, they only pronounce the second tone as the half second tone: only the first part of the standard second tone is pronounced, i.e., it starts with middle pitch and falls to low pitch.
(This is very similar to the half third tone in Mandarin.)
The Southern dialect
The Southern dialect is formally called phương ngữ Nam Bộ, colloquially giọng miền Nam, or giọng Nam for short.
The Southern dialect (Saigon a.k.a. HCM city) pronounces the tones quite differently from the standard language, requiring a separate post.
Six or eight?
There are debates whether there are six or eight tones in Vietnamese. The reason is obvious: because of the checked tones.
In reality, native speakers aren’t even aware of this debate. They were taught at school that there are six tones, and it’s crystal clear that the writing system also only has six tones. They are generally aware that when a syllable ends in p, k, c, or ch, it can only have either the third tone or the sixth tone. However, because the concept of tone feels so natural and intrinsic to native speakers, the six tones notion get along just fine. In fact, if not for (mass) education, people wouldn’t know that there is something called “tone” in their language.
For people who are learning Vietnamese, it’s best to treat the checked tones separately from normal tones because there are still subtle (or noticeable) differences.