There are six tones 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) |
It is easy to see that 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 symbol 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 with the other tones.
Out of the six tones, the fifth and sixth tones are the most difficult (fifth is more difficult), and it is not hard to guess why. They are also often the last to be mastered by native speakers. For example, young toddlers often 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, it can’t carry any of the six tones, only two of them. They are the third and sixth tones. When the third or sixth tone appears in such syllables, it is called a checked tone.
The pronunciation of each of the checked tones is a little different from that of its normal version. The checked tones are:
- Short (as short as the normal sixth tone, shorter than the other five), and so is the syllable that carries it.
- Level (no rising and no falling)
It is 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.
Remember 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.
Remember 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).
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 don’t really think much about this. They were taught at school that there are six tones, and it is crystal clear that the writing system also only has six tones, so six tones it is. They are generally aware of the fact that when a syllable ends in p, k, c or ch, we can only give it either the third tone or the sixth tone, not any other tone. However, because the concept of tone feels so natural and intrinsic to the 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, and there are six (or eight) of them.
For learners of Vietnamese, it is best to treat the checked tones separately from normal tones because there are still subtle (or not?) differences.
For a comparison, there are similar debates in other tonal languages. A prominent example is Cantonese, where people argue that there are nine tones instead of six.
Placement of tone marks
The placement of tone marks is governed by the spelling rules.
Tones in dialects
The Northern dialect
Tones in the Northern dialect (Hanoi) are for the most part the same as the standard tones. However, there is one difference: the second tone. In fact, the Northern dialect does 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, people pronounce the second tone as the half second tone, i.e., only the first part of the standard second tone is pronounced.
For a comparison, this phenomenon is very similar to that of the half third tone in Mandarin.
The Southern dialect
Tones in the Southern dialect behave quite differently from the standard tones, as elaborated in the article about tones in the Southern dialect.