你好 is pronounced ní hǎo, not nǐ hǎo. When two third-tone syllables appear together, the first one changes to a second tone. This rule — called tone sandhi (三声变调, sān shēng biàn diào) — is never reflected in pinyin spelling, which is why beginners get tripped up constantly.
What is the third tone, actually?
Chinese has four tones. The third tone is the dipping tone — it starts mid, drops low, then rises:
| Tone | Name | Pitch contour | Example |
|---|---|---|---|
| 1st | High-level | 5 → 5 (high and flat) | mā 妈 (mom) |
| 2nd | Rising | 3 → 5 (goes up) | má 麻 (hemp) |
| 3rd | Dipping | 2 → 1 → 4 (dips then rises) | mǎ 马 (horse) |
| 4th | Falling | 5 → 1 (drops sharply) | mà 骂 (scold) |
Here's the secret textbooks don't tell you: the full dipping third tone only happens when a syllable stands alone. In actual speech, the third tone almost never gets pronounced in its full form — and this is the single most common reason foreigners sound unnatural in Chinese.
Rule 1: Two third tones together → first becomes second tone
This is the rule you'll use every day. When two third-tone characters sit next to each other, the first one shifts to a second tone:
| Written | Pinyin says | Actually pronounced | Meaning |
|---|---|---|---|
| 你好 | nǐ hǎo | ní hǎo | Hello |
| 很好 | hěn hǎo | hén hǎo | Very good |
| 可以 | kě yǐ | ké yǐ | Can / OK |
| 所以 | suǒ yǐ | suó yǐ | Therefore |
| 水果 | shuǐ guǒ | shuí guǒ | Fruit |
⚠️ Critical: the pinyin spelling never changes. Your textbook still writes nǐ hǎo, and HSK exams test the original tones. But when you speak, you say ní hǎo. This is the trap — and why reading pinyin aloud without knowing tone sandhi makes you sound like a robot.
Rule 2: Three third tones in a row
When three third-tone characters appear consecutively, the grouping depends on meaning. The general pattern: the first two become second tone, the last stays third — but natural speech groups by word boundaries:
| Phrase | Grouping | Actual pronunciation | Meaning |
|---|---|---|---|
| 我很好 | 我 / 很好 | wǒ / hén hǎo | I'm very well |
| 展览馆 | 展览 / 馆 | zhán lán guǎn | Exhibition hall |
| 你好吗 | 你 / 好吗 | ní hǎo ma | How are you? |
The good news: you don't need to memorize this. Native speakers group by meaning instinctively, and with enough listening practice, so will you. For now, just know the pattern exists.
Rule 3: Third tone before any other tone → "half third tone"
When a third tone appears before a first, second, or fourth tone (or neutral tone), it becomes a half third tone: you only pronounce the falling part, skipping the rise entirely. It stays low — like you started to dip but never came back up.
| Example | Pinyin | What happens | Type |
|---|---|---|---|
| 很多 | hěn duō | hěn ↓ (low, no rise) + duō | 3rd + 1st |
| 美国 | měi guó | měi ↓ (low, no rise) + guó | 3rd + 2nd |
| 好看 | hǎo kàn | hǎo ↓ (low, no rise) + kàn | 3rd + 4th |
This is the rule you'll use most often — because third tones are far more likely to appear before other tones than next to another third tone.
One simple trick to remember it all
3rd + 3rd → 2nd + 3rd (the first one goes up)
3rd + anything else → half 3rd (cut off the tail, stay low)
Common mistakes
- Reading pinyin exactly as written. Pinyin deliberately does not mark tone sandhi — it shows the underlying tone, not the surface pronunciation. This is by design. You have to know the rules.
- Always pronouncing the full dipping third tone. Saying "hǎo" with a full dip-rise in the middle of a sentence sounds painfully slow and unnatural. In connected speech, third tones are almost always half-pronounced.
- Turning ALL three consecutive third tones into second tones. In 我很好 (wǒ hěn hǎo), only 很 changes (hén). 我 stays third because it's its own word group. Don't blindly apply the rule — listen for word boundaries.
Practice distinguishing tones with our free Tone Quiz — hear a syllable, pick which tone it is, and build the reflex that makes tone sandhi feel natural.
The bottom line
你好 = ní hǎo, not nǐ hǎo. Master this one rule and your Chinese instantly sounds twice as natural. The third tone is almost never pronounced in its full dipping form — it either becomes a second tone (before another third tone) or gets chopped in half (everywhere else).
FAQ
Does this rule apply to all third-tone words?
Yes — every two-syllable combination where both characters are third tone follows this rule, no exceptions. Common ones you'll encounter daily: 可以 (ké yǐ), 所以 (suó yǐ), 理解 (lí jiě, to understand), 奶粉 (nái fěn, milk powder), 影响 (yíng xiǎng, influence).
Do native speakers know they're doing this?
Most don't consciously think about it — just like English speakers don't think about how "want to" becomes "wanna" in fast speech. It's automatic. But when you point it out, they'll immediately recognize it's true.
Does this affect HSK listening tests?
Yes. HSK listening sections use natural speech, which means speakers apply tone sandhi. If you've only practiced reading pinyin as written, you won't recognize 可以 when you hear ké yǐ in the recording. Practice listening to real speech — our Tone Quiz is a good start.