Third-Tone Sandhi Beyond 你好: How Chains of Low Tones Behave

Core examples: 你好, 很好, 老板, 我想买, 你想去哪儿, 很有意思, 老虎很可爱. Recommended feature module: Pitch-contour animation for grouped phrases, with toggles for citation tone, half-third tone, and sandhi realization. Related internal articles: 036, 038, 044, 045, 046, 047, 058, 063, 065.

你好 is only the doorway

Most learners meet third-tone sandhi through 你好:

nǐ + hǎo → ní hǎo

Two third tones occur together. The first is pronounced like a second tone.

That rule is real and useful. But it is not enough.

Third tone is the most context-sensitive tone in Mandarin. It changes in chains, shortens in connected speech, interacts with word boundaries, and often appears as a low “half-third” rather than the full falling-rising citation form taught at the beginning.

The problem is not that textbooks lie. The problem is that they introduce the clearest version first. Real speech adds timing, grouping, and rhythm.

Better learner principle:

Third tone is not one sound shape.
It is a family of surface shapes controlled by context.

1. Citation third tone versus half-third tone

The citation form of third tone is often described as low falling-rising:

mǎ
hǎo
wǒ
nǐ

In isolation, a speaker may pronounce a clear dip and rise. But before another syllable, especially in normal speech, the rise is often reduced or absent.

Compare:

好。          Hǎo.       Good. / Okay.
好吃。        hǎochī     tasty
我去。        wǒ qù      I’ll go.
很忙。        hěn máng   very busy

In 好吃, 我去, and 很忙, the third-tone syllable before a non-third tone is commonly low and short, not a full theatrical dip.

This “half-third” is crucial. It prevents learners from over-pronouncing every third tone.

2. The basic 3+3 rule

When two third-tone syllables occur together, the first changes to a second-tone-like contour.

Important: Pinyin normally still writes the dictionary tones:

你好 nǐ hǎo

It does not usually respell the sandhi pronunciation as ní hǎo in ordinary orthography. Learners must know that written Pinyin often shows underlying citation tones, while speech applies sandhi.

3. Third tone before non-third tone

A third tone before a first, second, fourth, or neutral-tone syllable usually remains third tone in the underlying sense, but it is often realized as a low half-third.

Learner mistake:

wǒ shuō = wǒ̌̌̌ shuō

with a big drawn-out dip on 我. That sounds unnatural.

Better:

Keep 我 low and brief, then move into 说.

This is why a learner who “knows tones” in flashcards may still sound choppy in speech. The issue is not the tone label; it is the connected-speech realization.

4. Three third tones in a row: grouping matters

Now consider a chain:

我想买。
wǒ xiǎng mǎi
I want to buy.

All three syllables are third tone in dictionary form. Natural pronunciation depends on how the phrase is grouped.

One likely grouping:

我 + 想买

想买 is a 3+3 pair, so 想 becomes second-tone-like:

wǒ xiáng mǎi

The 我 before 想 may be low or may also be affected depending on rhythm and emphasis, but learners should not blindly turn every third tone except the last into a second tone. The phrase is processed in chunks.

Another example:

你想买什么？
nǐ xiǎng mǎi shénme

Possible grouping:

你 + 想买 + 什么

Here 想买 again behaves as a pair. 你 is a pronoun and may be light depending on context.

A more formal way to put it:

Third-tone sandhi is sensitive to prosodic grouping.

For learners:

Mark word groups first. Then apply sandhi inside and across likely groups.

5. Four-syllable chains: do not calculate like a robot

Consider:

很有意思。
hěn yǒu yìsi
very interesting

Here 很 and 有 are third tones; 意思 begins with fourth tone and ends neutral. The phrase is not four third tones, but it still shows how third tones sit inside rhythm.

Now consider:

老虎很可爱。
lǎohǔ hěn kě'ài
The tiger is very cute.

Underlying third tones appear in 老, 虎, 很, 可.

Likely grouping:

老虎 / 很可爱

Within 老虎, 3+3 sandhi applies:

lǎohǔ → láohǔ

In 很可爱, 很 and 可 may form a 3+3 environment depending on speech rhythm:

hěn kě'ài → hén kě'ài

But learners should not approach this as a math puzzle only. Native speakers are not computing tone labels consciously. They are speaking in words and phrases.

Practical sequence:

1. Identify words: 老虎 / 很 / 可爱.
2. Identify tight groups: 老虎, 很可爱.
3. Apply 3+3 where third tones are adjacent in the spoken group.
4. Keep non-final third tones low or sandhi-shaped, not over-dipped.

6. Word boundaries matter, but not absolutely

Word boundaries influence sandhi, but speech grouping can cross word boundaries.

Example:

你很好。
nǐ hěn hǎo
You are very good.

The words may be:

你 / 很 / 好

But in speech, 很好 forms a tight adjective phrase. 很 changes before 好:

hěn hǎo → hén hǎo

The pronoun 你 may also interact depending on rhythm:

你很好。

Some learners are taught to pronounce it roughly as:

ní hén hǎo

Others may hear a lighter low 你 followed by 很好. The exact surface depends on speed, emphasis, and grouping.

The safe learner method:

Learn common phrases as phrases, not as tone arithmetic.

High-frequency chunks:

7. Why classroom third tone creates listening problems

Many learners overproduce third tone because classroom drills reward visible effort. A full dip sounds like you are “doing the tone.” But natural Mandarin often hides the rise.

This creates two listening problems.

First, learners expect native speakers to pronounce a full dip every time. When native speakers use half-third tones, learners fail to recognize them.

Second, learners produce speech that is too slow and segmented:

Wǒ̌ xiǎ̌ng mǎ̌i...

instead of a smoother phrase.

A better practice phrase:

我想买一点儿。
wǒ xiǎng mǎi yìdiǎnr

Practice it in groups:

我想 / 买一点儿
我 / 想买 / 一点儿

Listen to where pitch actually rises and where it stays low.

8. Third tone and emphasis

Emphasis can make a third tone fuller.

Compare:

我去。
Wǒ qù.
I’ll go.

In ordinary speech, 我 may be low and short.

But if someone asks:

谁去？
Who is going?

You might answer:

我去。
Wǒ qù.
I’m the one going.

Here 我 may receive more stress and a fuller contour. This does not contradict the half-third rule. It shows that tone realization depends on information structure.

Learners need both forms:

ordinary low third tone
emphatic fuller third tone

If every third tone is emphatic, nothing is emphatic.

9. A drill system for third-tone chains

Use real word groups, not nonsense strings.

Level 1: two-syllable 3+3

你好
很好
老板
可以
哪里
水饺

Task: make the first syllable rise like second tone, but do not over-lengthen it.

Level 2: 3 before non-3

我说
很忙
想去
可以买
你来

Task: keep the third-tone syllable low and short before the next tone.

Level 3: three-syllable chunks

我想买
你想走
很有名
小老板

Task: mark grouping before speaking.

Level 4: phrase practice

你想去哪儿？
我想买这个。
这个很好吃。
老虎很可爱。

Task: record yourself. Listen for over-dipped third tones.

Level 5: conversation frames

A: 你想买什么？
B: 我想买点儿水果。

A: 这个怎么样？
B: 很好，但是有点儿贵。

Task: preserve sandhi while speaking naturally.

10. Tool concept: third-tone grouping board

The Inkuntri module should show a phrase such as:

你想买什么？

Users can drag grouping brackets:

[你] [想买] [什么]

The tool then displays:

The module should let users hear:

citation reading
slow grouped reading
natural-speed reading

The visual pitch trace should highlight that real speech is not a row of identical textbook dips.

A practical grouping algorithm for third-tone chains

Third-tone sandhi becomes less mysterious when the reader stops looking at a row of syllables and starts looking at groups. The natural unit is usually a word, fixed expression, or short phrase chunk.

Use this algorithm:

1. Mark the word boundaries you already know.
2. Group unknown material into likely two-syllable chunks.
3. Apply 3+3 sandhi inside the closest group first.
4. Read the remaining third tones as low/half-third before non-third tones.
5. Recheck at phrase speed; adjust if the grouping sounds unnatural.

This is not a mechanical rule engine. It is a reading and listening method. Real speech depends on speed, emphasis, and phrase structure, but the method prevents the worst learner habit: dipping every third tone fully.

Consider:

我想买点儿水果。
wǒ xiǎng mǎi diǎnr shuǐguǒ

A beginner may see five third-tone syllables or near-third-tone items and panic. A better grouping is:

我 | 想买 | 点儿 | 水果

At natural speed, you do not pronounce a dramatic full dip on every third-tone syllable. You organize the phrase into chunks. Some syllables undergo sandhi; others remain low and short because they are followed by non-third tones or because the phrase moves on.

Three-syllable chains: two common shapes

The most teachable three-syllable chains are 1+2 grouping and 2+1 grouping.

The exact examples can vary by speaker and context, but the lesson is stable: do not treat three third tones as equal beads on a string. Find the phrase structure.

A useful classroom drill:

很好 / 我很好 / 我也很好
老板 / 老老板 / 老老板来了
可以 / 也可以 / 我也可以

In each line, the learner first masters the two-syllable core, then adds material around it.

The half-third tone deserves its own practice

Many textbooks introduce the third tone as a falling-rising contour. That is the citation form. In ordinary connected speech, a third tone before a first, second, fourth, or neutral tone is usually better practiced as low rather than fully dipping and rising.

Examples:

北京       běijīng      3-1
语言       yǔyán        3-2
主要       zhǔyào       3-4
你的       nǐ de        3-neutral

A learner who fully dips in all of these will sound overcareful and slow:

běi↘↗ jīng   yǔ↘↗ yán   zhǔ↘↗ yào

The better training cue is:

low + next tone

This is especially important for common phrases:

我去       wǒ qù
你说       nǐ shuō
很好       hěn hǎo   (with 3+3 sandhi inside the phrase)
可以       kěyǐ      (often lexicalized, with sandhi behavior learners should hear as a word)

Practice half-third tones by recording short phrases, not isolated syllables. A full isolated wǒ is useful for showing the category, but it is not what carries most connected speech.

Emphasis can temporarily restore fuller tone shapes

One reason third-tone rules feel inconsistent is that emphasis changes delivery. A speaker correcting someone, contrasting alternatives, or reading slowly may give a fuller realization than in casual speech.

Compare:

A: 你姓李吗？
B: 我姓马。不是李，是马。

The second 马 may be pronounced with a clearer full third tone because it is contrastive. In ordinary flow, the same syllable might be shorter and lower.

This does not mean the rules are fake. It means pronunciation has layers:

citation form
ordinary phrase form
emphatic form

Learners should know all three, but production practice should prioritize ordinary phrase form. If every third tone is pronounced like a dictionary demonstration, the sentence sounds like it is being carved syllable by syllable.

Listening drills that target sandhi rather than spelling

A sandhi drill should hide the written tone marks at first. Otherwise learners “hear” what they see.

A strong drill sequence:

1. Hear: 你好
2. Choose: 2-3 or 3-3 as pronounced?
3. Reveal: written nǐ hǎo, pronounced near ní hǎo
4. Repeat with pitch contour.
5. Place it in a sentence: 你好，我想问一下。

Use word families:

The point is to make sandhi automatic at the word and phrase level. Learners should not be calculating tone changes while trying to speak.

Final learner takeaway

Third-tone sandhi is not just 你好.

A serious learner needs four ideas:

3+3: first third tone becomes second-tone-like.
3 before non-3: often low/half-third, not full dip.
Chains: grouping matters.
Emphasis: can restore a fuller contour.

Do not learn third tone as a shape you paste everywhere. Learn it as a low-tone system that adapts to words, phrases, and speech rhythm.