A few tones change depending on the syllable that follows. There are three rules worth learning: the third tone before another third tone, 一 yī, and 不 bù. Pinyin in dictionaries shows the original tones for the third-tone rule, but on this site (and in most textbooks) 一 and 不 are written with the tone you actually say.
When two third tones come together, the first one is said as a second tone. 你好 is written nǐ hǎo but said ní hǎo. Pinyin keeps the written ǐ, so you have to apply this one yourself.
Words from the readings where it applies:
In a run of three or more third tones, group them by meaning and change all but the last in each group: 我很好 wǒ hěn hǎo is usually said wó hén hǎo.
| When | Say | Examples from the readings |
|---|---|---|
| On its own, counting, in dates, numbers and ordinals, or at the end | yī (first) | 第一dì yī唯一wéiyī星期一xīngqīyī之一zhī yī十一shíyī二十一èrshíyī |
| Before a fourth tone (and before 个 gè) | yí (second) | 一个yí ge一样yíyàng一下yíxià一次yí cì一定yídìng一位yí wèi一件yí jiàn一旦yídàn |
| Before a first, second or third tone | yì (fourth) | 一起yìqǐ一边yìbiān一些yìxiē一直yìzhí一种yì zhǒng一点yìdiǎn一杯yì bēi一家yì jiā |
| When | Say | Examples from the readings |
|---|---|---|
| Before a fourth tone | bú (second) | 不是bú shì不用bú yòng不会bú huì不过búguò不断búduàn不要bú yào不再bú zài不太bú tài |
| Everywhere else | bù (fourth) | 不如bùrú不仅bùjǐn不同bùtóng不少bù shǎo不能bù néng不好bù hǎo不妨bùfáng不该bù gāi |
In the middle of a verb phrase 不 is often light and toneless: 听不懂 tīng bu dǒng, 对不起 duì bu qǐ.
To hear every syllable in all four tones, use the pinyin chart with audio.