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TaiwaneseTone Sandhi Made Simple: The Third Tone and Other Tone Change Rules
TL;DR: Tone sandhi is the way a tone changes depending on the tones around it. In Mandarin, three changes cover most of what you will meet early. When two third tones come in a row, the first is said as a second tone, so 你好 (nǐ hǎo) is said close to ní hǎo. The word 不 (bù) becomes bú before a fourth tone. The number 一 (yī) becomes yí before a fourth tone and yì before the others. These changes are mostly not written in Pinyin, so you learn them by ear and as whole phrases.
Key takeaways:
- A tone change affects how a word is said, not its base tone. The tone in a dictionary stays the same.
- Two third tones in a row: the first is said as a second tone, as in 你好 (nǐ hǎo), said ní hǎo.
- 不 (bù) becomes bú before a fourth tone, as in 不是 (bú shì).
- 一 (yī) becomes yí before a fourth tone and yì before the first, second and third tones. It stays yī when counting.
- The third tone change is not normally written in Pinyin, and textbooks differ on 不 and 一.
Tone sandhi is the part of our complete guide to Chinese pronunciation that surprises learners most. You learn that 你好 (nǐ hǎo) is two third tones, and then a native speaker says something closer to ní hǎo. This page explains the changes that matter first, shows them with real words, and flags the parts that vary from speaker to speaker.
You do not need to memorise everything on day one. These are patterns you will hear constantly, and the practice section shows how to pick them up as whole phrases. If you are still learning what the four tones sound like, start with our guide to Chinese tones and come back.
Tone Sandhi in Mandarin | What It Is and Why It Happens
Third Tone Sandhi | The 3-3 Rule Explained
Half-Third Tone | What the Third Tone Does Everywhere Else
Three Third Tones in a Row | It Depends on the Words
不 Tone Change | When bù Becomes bú
Tone Sandhi in Pinyin | How Tone Changes Are Written
Tone Sandhi Practice | How to Learn the Changes
Tone Sandhi in Mandarin: What It Is and Why It Happens
Tone sandhi is a change in how a tone is pronounced when it sits next to certain other tones or words. In Mandarin it is small and regular: it affects the third tone, the word 不 (bù) and the number 一 (yī). The tone written in a dictionary is the base tone, and the spoken tone can differ from it.
| Change | Trigger | What you say | Example |
|---|---|---|---|
| Third tone before a third tone | Another third tone follows | The first becomes a second tone | 你好 (nǐ hǎo), said ní hǎo |
| Half-third tone | A first, second or fourth tone follows | Only the low part, no final rise | 好吃 (hǎochī), said with a low 好 |
| 不 (bù) | A fourth tone follows | Becomes bú | 不是 (bú shì) |
| 一 (yī) | Another tone follows, unless you are counting or using it as an ordinal | Becomes yí before a fourth tone, yì before the others | 一个 (yí gè), 一天 (yì tiān) |
Why do these changes exist? A common explanation is that two dipping tones in a row are awkward to say, so the first gives way. That describes the pattern. You do not need to explain it to yourself in order to use it.
Third Tone Sandhi | The 3-3 Rule Explained
When two third tones come in a row, the first one is said as a second tone. So 你好 (nǐ hǎo) is said close to ní hǎo. The second third tone stays as it is. The Pinyin spelling does not change: you still write nǐ hǎo, but you say the first syllable with a rising tone.
| Characters | Written Pinyin | What you say | Meaning |
|---|---|---|---|
| 你好 | nǐ hǎo | ní hǎo | hello |
| 可以 | kěyǐ | kéyǐ | can, may |
| 所以 | suǒyǐ | suóyǐ | so, therefore |
| 很好 | hěn hǎo | hén hǎo | very good |
| 水果 | shuǐguǒ | shuíguǒ | fruit |
| 老鼠 | lǎoshǔ | láoshǔ | mouse, rat |
| 有点 | yǒudiǎn | yóudiǎn | a little, somewhat |
Say ní hǎo out loud: a rising first syllable and a low second one. That is the shape native speakers use for this word.
The rule applies only to a third tone before another third tone. Before a first, second or fourth tone, the third tone does not turn into a second tone. It becomes a half-third tone, which is the next section.
Half-Third Tone: What the Third Tone Does Everywhere Else
The full third tone, which dips and then rises, is mostly heard when a syllable is said alone or at the end of a phrase. Before any other tone, the third tone is usually said as just its low part, without the final rise. This is called the half-third tone, and it is very common in real speech.
| Where the third tone is | What you hear | Example |
|---|---|---|
| Alone or at the end of a phrase | The full dip and rise | 好 (hǎo), 水 (shuǐ) |
| Before a first, second or fourth tone | The low part only, a half-third | 好吃 (hǎochī), 好人 (hǎorén), 好看 (hǎokàn) |
| Before another third tone | Becomes a second tone | 你好 (nǐ hǎo), said ní hǎo |
Textbooks differ in how much they stress the half-third tone, and it is easier to hear than to describe. A native teacher can show you the sound in a few seconds. The neutral tone is also described as tending to sound higher after a third tone, a related effect covered in our guide to Chinese tones.
Three Third Tones in a Row | It Depends on the Words
With three third tones in a row, the result depends on how the words group, so there is no single pattern. If the first two syllables form a unit, both usually become second tones. If the last two form the unit, the middle one changes and the first stays a third tone, usually the half-third. Speakers vary.
| Words | How they group | Written Pinyin | What you say |
|---|---|---|---|
| 展览馆 | (展览) + 馆 | zhǎnlǎn guǎn | zhán lán guǎn |
| 纸老虎 | 纸 + (老虎) | zhǐ lǎohǔ | zhǐ láohǔ |
| 我很好 | Speakers differ | wǒ hěn hǎo | wó hén hǎo, or wǒ hén hǎo |
不 Tone Change: When bù Becomes bú
不 (bù) means no or not, and it is normally a fourth tone. Before another fourth tone it becomes a second tone, bú, so 不是 (bú shì) is said with a rising 不. Before a first, second or third tone it stays bù, as in 不吃 (bù chī), 不来 (bù lái) and 不好 (bù hǎo).
| The next tone is | 不 is pronounced | Example |
|---|---|---|
| Fourth | bú | 不是 (bú shì), 不对 (bú duì), 不去 (bú qù) |
| First | bù | 不吃 (bù chī), 不说 (bù shuō) |
| Second | bù | 不来 (bù lái), 不能 (bù néng) |
| Third | bù | 不好 (bù hǎo), 不想 (bù xiǎng) |
| Between two copies of a word in an A-not-A question | Often light | 是不是 (shì bu shì) |
一 Tone Change | yī, yí and yì
一 (yī) means one. On its own, when counting, as an ordinal, or at the end of a word, it stays yī. Before a fourth tone it becomes yí, as in 一个 (yí gè), and before a first, second or third tone it becomes yì, as in 一天 (yì tiān).
| Situation | 一 is pronounced | Example |
|---|---|---|
| Counting, alone, or at the end of a word | yī | 一二三 (yī èr sān), 十一 (shíyī) |
| Ordinal, meaning “first” | yī | 第一 (dì yī), 第一个 (dì yī gè) |
| Before a fourth tone | yí | 一个 (yí gè), 一次 (yí cì), 一样 (yí yàng) |
| Before a first tone | yì | 一天 (yì tiān), 一般 (yì bān), 一些 (yì xiē) |
| Before a second tone | yì | 一年 (yì nián), 一直 (yì zhí) |
| Before a third tone | yì | 一起 (yì qǐ), 一点 (yì diǎn) |
Tone Sandhi in Pinyin: How Tone Changes Are Written
The third tone change is not normally written in Pinyin, so 你好 (nǐ hǎo) keeps its two third-tone marks. The Chinese Pronunciation Wiki notes that some textbooks and software mark changes with a dot under the letter, but that this is not standard Pinyin. For 不 and 一, practice varies between textbooks.
| Item | Typical written Pinyin | What you say | What to know |
|---|---|---|---|
| 你好 | nǐ hǎo | ní hǎo | The third tone change is generally unmarked |
| 不是 | bù shì or bú shì | bú shì | Both appear in learning materials |
| 一个 | yī gè or yí gè | yí gè | Both appear, so check your textbook |
| 不 and 一 in a dictionary | bù, yī | Varies with context | The entry shows the base tone |
Read the tone mark as the base tone of the word and apply the change when you speak. Our guide to what Pinyin is and how it works explains the system, and our guide to Chinese tones covers tone marks and how to type them.
Tone Sandhi Practice: How to Learn the Changes
Learn tone changes as whole phrases, not as rules to work out while you speak. Start with 你好 (nǐ hǎo), 不是 (bú shì) and 一个 (yí gè), then add common words one at a time. Hearing native audio and getting correction matter more than memorising the rule.
There is no fixed timetable for this, and progress depends on your starting point and how consistently you practise. What matters more is the order.
- Learn the four tones on single syllables first. Say mā, má, mǎ and mà and check that you can hear the difference, since every tone change builds on the four basic tones.
- Start with 你好 and say it as ní hǎo. Practise 你好 (nǐ hǎo) as ní hǎo, then other words made of two third tones, such as 可以 (kěyǐ), 水果 (shuǐguǒ) and 老鼠 (lǎoshǔ).
- Learn 不 and 一 inside real phrases. Memorise 不是 (bú shì), 不对 (bú duì), 一个 (yí gè) and 一天 (yì tiān) as whole chunks instead of working out the rule each time.
- Say the half-third tone in the middle of a phrase. Before a first, second or fourth tone, say the third tone as its low part only, without the final rise, and keep the full dip and rise for syllables said alone or at the end of a phrase.
- Listen for the changes in native audio. Replay short native recordings and notice where the tone you hear differs from the tone written in Pinyin.
- Record yourself and get native correction. Record the same phrases, compare them with a native recording, and ask a native teacher about runs of three third tones, where speakers vary.
Our guide to Chinese listening practice covers how to train your ear, and our free Mandarin pronunciation trainer is a place to practise sounds between lessons.
Tone Sandhi Mistakes | What Learners Get Wrong
Most tone sandhi errors come from applying a rule too widely. The 3-3 rule applies only before another third tone, 不 changes only before a fourth tone, and 一 stays yī when you count. These are the five most common errors, and a native teacher can spot them in seconds.
| Mistake | Why it happens | Fix |
|---|---|---|
| Turning every third tone into a second tone | Over-applying the 3-3 rule | Only a third tone before another third tone becomes a second tone. Elsewhere, use the half-third |
| Saying 你好 (nǐ hǎo) with two full dips | Reading the tone marks literally | Say ní hǎo |
| Changing 一 when counting | Over-applying the 一 rule | 一二三 (yī èr sān) keeps yī |
| Changing 不 before a first, second or third tone | Over-applying the 不 rule | 不 becomes bú only before a fourth tone |
| Trying to work out long runs of third tones on the spot | Treating a flexible pattern as a fixed rule | Learn common phrases as chunks and copy native audio |
Where to Go Next
| If you want to | Read this |
|---|---|
| Learn how each of the four tones is produced | Our guide to Chinese tones |
| Train your ear for the differences | Our guide to Chinese listening practice |
| Understand what Pinyin is | Our guide to what Pinyin is and how it works |
| Practise speaking with feedback | Our guide to Chinese speaking practice |
| See why tones are hard for English speakers | Our guide to why Mandarin is genuinely hard to learn |
Frequently Asked Questions (FAQs)
What is tone sandhi?
Tone sandhi is the way a tone changes when it sits next to other tones or words. In Mandarin the changes you meet first involve two third tones in a row, 不 (bù) and 一 (yī). The tone written in a dictionary and the tone you say can differ, as in 你好 (nǐ hǎo), which is said close to ní hǎo.
Does Mandarin have tone sandhi?
Yes. Mandarin has a small, regular set of tone changes, and the third tone change is the most important one. The others affect 不 (bù) and 一 (yī). Mandarin’s system is light compared with Southern Min, where, according to Wikipedia, in most cases every syllable changes into a different tone.
What is the 3-3 tone rule in Mandarin?
When two third tones come in a row, the first one is said as a second tone. So 你好 (nǐ hǎo) is said close to ní hǎo, and 可以 (kěyǐ) is said close to kéyǐ. The written Pinyin does not change.
What are the tone sandhi rules in Mandarin?
There are three to learn first: a third tone before another third tone, 不 (bù) before a fourth tone, and 一 (yī) before other tones. The first of two third tones becomes a second tone. 不 becomes bú before a fourth tone, as in 不是 (bú shì). 一 becomes yí before a fourth tone and yì before the first, second and third tones, as in 一个 (yí gè) and 一天 (yì tiān).
What happens when there are three third tones in a row?
It depends on how the words group, so there is no single pattern. When the first two syllables form a unit, both usually become second tones, as in 展览馆 (zhǎnlǎn guǎn). When the last two form the unit, only the middle one changes, as in 纸老虎 (zhǐ lǎohǔ). Speakers vary, so learn common phrases as whole chunks.
How do 不 (bù) and 一 (yī) change tone?
不 (bù) becomes bú before a fourth tone, and 一 (yī) becomes yí before a fourth tone or yì before the other tones. Counting and ordinals keep yī, as in 第一 (dì yī). Some textbooks write the changed tone and some write the base tone, so check which one yours uses.
Do I need to learn tone sandhi?
It is worth learning the common changes early, mostly by hearing and copying whole phrases rather than memorising rules. Phrases like 你好 (nǐ hǎo), 不是 (bú shì) and 一个 (yí gè) are so frequent that the changed version becomes a habit. A native teacher can tell you quickly whether a change sounds natural.
Does Cantonese have tone sandhi?
Not in the Mandarin sense. Wikipedia describes a process in Cantonese called changed tone, which applies only in certain semantic domains and is treated as derivational rather than as sandhi. Southern Min (Hokkien), by contrast, has a complex tone sandhi system.
What is the phonemic tone of Mandarin?
Mandarin has four tones plus a neutral tone, and each tone can change which word you are saying. For example, 妈 (mā), 麻 (má), 马 (mǎ) and 骂 (mà) differ only in tone. Tone sandhi changes how a tone is pronounced in context, but Pinyin still writes 你好 as nǐ hǎo.
Tone Changes Are Easiest to Learn With Someone Listening
Reading the 3-3 rule is the easy part. The hard part is hearing whether your ní hǎo rises the way a native speaker’s does, and that is difficult to judge in your own voice.
Flexi Classes runs live 60-minute Mandarin classes with native teachers in small groups of up to five students, with real-time correction on pronunciation and tones. The 7-day free trial is a direct way to find out how your tone changes actually sound.