Definition:
Tone sandhi is a phonological process in which the realization of a lexical tone changes depending on the tones of adjacent syllables in connected speech. The term derives from Sanskrit sandhi (junction/combination). In Mandarin grammar, the most regular tone sandhi rule affects Tone 3: when two Tone 3 (dipping) syllables are adjacent, the first changes to Tone 2 (rising) — the canonical example being ni hao (你好 — hello), which is pronounced ní hao in natural speech, though both syllables are lexically Tone 3 in citation form. Tone sandhi is important for both accurate production of Mandarin and for understanding the relationship between lexical tone representation and phonetic output.
Mandarin Tone 3 Sandhi
The core rule:
> Tone 3 + Tone 3 ? Tone 2 + Tone 3
| Lexical form | Pronunciation | Example |
|---|---|---|
| ni hao (T3 + T3) | [ní hao] | 你好 — hello |
| wo ye (T3 + T3) | [wó ye] | 我也 — I also |
| lao shu (T3 + T3) | [láo shu] | 老鼠 — rat |
Note: The change is phonetic (in pronunciation) but not typically reflected in orthography — both syllables are still written with Tone 3 markers.
Sequences of Three or More Tone 3 Syllables
In longer Tone 3 sequences, only the last Tone 3 syllable retains Tone 3; preceding syllables become Tone 2:
- ???? ? ní háo ní hao (greeting + response)
Tone 4 Sandhi with ? (bù)
? (bù) is normally Tone 4, but changes to Tone 2 before another Tone 4 syllable:
- bù shì (不是 — not be): bú shì in pronunciation
Tone Sandhi in Other Chinese Languages
Tone sandhi is far more complex in other Chinese varieties:
- Shanghainese (Wu): Domain-based sandhi operates over entire phonological phrases
- Hokkien/Min Nan: Has a complete tone sandhi paradigm affecting all tones except the “base” tone
- Cantonese: Relatively little tone sandhi compared to other Chinese varieties
History
Tone sandhi reflects a general phonological tendency toward assimilation in connected speech — isolated citation tones are modified under the influence of adjacent tonal contexts. The Tone 3 sandhi in Mandarin reflects an avoidance of two consecutive low-dipping contours, an effort-economy principle in articulation.
Common Misconceptions
- “Ni hao is pronounced exactly as written/marked” — The Tone 3 sandhi means the first syllable is actually pronounced as Tone 2 in natural speech; learners who practice only in isolation may have accent issues
- “Tone sandhi only happens in Mandarin” — Tone sandhi is cross-linguistically widespread in tonal languages
Criticisms
- Mandarin pronunciation courses sometimes ignore tone sandhi or treat it as “advanced”; it affects one of the most frequent expressions in the language (ni hao) and should be addressed from day one
Social Media Sentiment
Tone sandhi is an often-surprising discovery for intermediate Mandarin learners: “Wait, 你好 is actually said as Tone 2 + Tone 3?” generates many engagement posts. Last updated: 2026-04
Practical Application
- Flag Tone 3 sandhi at the point of teaching ni hao — learners should not internalize incorrect tone patterns for the most frequent Mandarin greeting
- Teach bù ? bú sandhi alongside the negation structure, not as an advanced topic
Related Terms
See Also
Research
- Duanmu, S. (2000). The Phonology of Standard Chinese. Oxford University Press. — Standard phonological reference including detailed treatment of Mandarin tone sandhi.
- Yip, M. (2002). Tone. Cambridge University Press. — Cross-linguistic treatment of tonal phonology including sandhi phenomena.
- Chen, M. Y. (2000). Tone Sandhi: Patterns across Chinese Dialects. Cambridge University Press. — Comprehensive cross-dialectal study of Chinese tone sandhi systems.