Chinese Tone Sandhi: Third Tone, Yī, and Bù in Real Speech

HSK Study Notes Editorial Team ·

In a dictionary every word carries a fixed tone, but in connected speech the tone in front can change so the words are easier to say and to hear. This is called tone sandhi. It is not a list of exceptions to memorise; it is what fluent speech already does. Keep the dictionary tone in your notes, and change the sound only when you read the phrase aloud. For the four tones themselves, start with Chinese tones explained.

Two third tones in a row

When two third tones meet, the first one is said as a second tone. 你好 (nǐ hǎo, “hello”) is actually pronounced like “ní hǎo.” You do not rewrite the pinyin — the change lives in the speaking, not on the page.

With three or more, group the phrase. 我很好 (wǒ hěn hǎo, “I’m fine”) is usually read wó hén hǎo. In fast speech the grouping shifts, so first make the two-syllable change automatic.

The half third tone

A third tone before any non-third tone is usually not fully dipped and raised again. You drop to the low point and stop — a half third tone. It keeps your rhythm from sagging on every third tone.

The shifting tones of 一 (yī) and 不 (bù)

  • 不 (bù, “not”) becomes bú before a fourth tone: 不是 (bú shì, “is not”), 不对 (bú duì, “not right”), 不会 (bú huì, “won’t / can’t”). Before any other tone it stays bù.
  • 一 (yī, “one”) becomes yí before a fourth tone — 一个 (yí ge, “one [item]”) — and yì before a first, second, or third tone: 一天 (yì tiān, “one day”), 一年 (yì nián, “one year”), 一起 (yìqǐ, “together”). When you count in isolation or read a number in order, it stays yī.

Turning the rules into speech

  1. Check the word once in its dictionary tones.
  2. Listen to the two-syllable phrase and mark only the syllable that changed.
  3. Say the phrase three times, and record the last one.
  4. Put it in a sentence and check that neither end has gone flat.

You do not need to recite the rule before you speak. Learn frequent chunks as fixed shapes of sound — 你好 (nǐ hǎo), 不会 (bú huì), 一个人 (yí ge rén, “one person”). If sandhi still feels slippery, go back to telling tones apart and make the single-syllable movements bigger before you combine them.