Tone Sandhi Analyzer
Tones change in real speech. Paste Chinese and see exactly which syllables shift — third-tone sandhi (3 + 3 → 2 + 3), 不 (bù) and 一 (yī) — with the written tone and the spoken tone side by side.
What is tone sandhi?
Tone sandhi is the way a syllable's tone changes because of the tone next to it. Dictionaries and pinyin always show the original (citation) tone, but in real speech some of those tones shift — so learners who memorise tones in isolation often sound wrong in conversation. This analyser applies the main Mandarin sandhi rules and shows the written tone and the spoken tone side by side.
The main Mandarin tone sandhi rules
| Rule | Change | Example (written → spoken) |
|---|---|---|
| Third-tone sandhi | 3 + 3 → 2 + 3 | 你好 nǐ hǎo → ní hǎo |
| Run of third tones | all but the last → 2 (depends on phrasing) | 我很好 wǒ hěn hǎo → wó hén hǎo |
| 不 (bù) | 4 → 2 before another 4th tone | 不是 bù shì → bú shì |
| 一 (yī) | 1 → 2 before a 4th tone | 一样 yī yàng → yí yàng |
| 一 (yī) | 1 → 4 before 1st, 2nd or 3rd tone | 一天 yī tiān → yì tiān |
Why the dictionary still shows the original tone
Pinyin is conventionally written with citation tones, and the sandhi change happens only when you speak. That is why 你好 is always written nǐ hǎo even though it is pronounced ní hǎo. Reading the citation tone keeps spelling consistent; this tool shows you the spoken version so you can train your pronunciation.
How to use it
Paste any Chinese sentence. Each syllable is shown with its written pinyin; syllables that change are highlighted with an arrow to the tone you should actually say, and the rule that caused it. Great for checking phrases with several third tones, or with 不 and 一.
Frequently asked questions
What is tone sandhi in Mandarin?
Tone sandhi is when a syllable's tone changes because of the tone next to it. The most common case is two third tones in a row: the first becomes a second tone (nǐ hǎo is said ní hǎo).
Which rules does this cover?
Third-tone sandhi over runs of third tones, the 不 (bù) rule (becomes second tone before a fourth tone), and the 一 (yī) rule (second tone before a fourth tone, fourth tone before others).
Why does the dictionary still write the original tone?
Pinyin is written with citation (dictionary) tones; the sandhi change happens only in pronunciation. This tool shows both so you read correctly and speak correctly.