You open your textbook. You see the Pinyin for "Hello": Nǐ Hǎo. You see two "dipping" marks (ˇ). You try to pronounce them both: Niiiii (down-up) Haaaaao (down-up).
It is exhausting. It is slow. And if you say it that way in Beijing, people will think you are a robot running low on battery.
Native speakers do not pronounce the tones exactly as they are written in Pinyin. They use Tone Sandhi (变调)—a set of flow rules that change tones depending on the characters next to them.
For HSK students, this is the #1 reason for missed points in listening exams. You hear a 2nd tone, you write a 2nd tone character, but the answer was actually a 3rd tone character masked by Sandhi rules.
In this guide, we break down the logic of the "Change," fix the common "Full Tone" mistake, and explain why the 3rd tone rarely sounds like a 3rd tone.
The Definition: What is the "True" 3rd Tone?
Before changing it, we must define it. The Standard 3rd Tone is often taught as "Falling-Rising" (Pitch value: 2-1-4).
- How it feels: Deep, guttural, dipping low and bouncing back up.
- When do you hear it? ONLY when the word is spoken alone or at the very end of a sentence.
The Reality: In continuous spoken sentences, the "Rising" part of the 3rd tone is almost always deleted to save time.
Rule 1: The "Ni Hao" Rule (3 + 3 = 2 + 3)
This is the most famous rule, but also the most confusing for beginners reading Pinyin.
The Law: When two 3rd Tones appear side-by-side, the first one turns into a 2nd Tone (Rising). The second one stays 3rd.
Logic: Pronouncing two dips (∨ + ∨) takes too much breath. It is physically easier to slide up, then down (ˊ + ∨).
Essential HSK Examples:
- 你好 (Nǐ + Hǎo) -> Pronounced: Ní Hǎo.
- 很冷 (Hěn + Lěng) -> Pronounced: Hén Lěng. (Very cold).
- 老虎 (Lǎo + Hǔ) -> Pronounced: Láo Hǔ. (Tiger).
- 可以 (Kě + Yǐ) -> Pronounced: Ké Yǐ. (Can / Okay).
Listening Trap: Even though it sounds like a 2nd tone, the Pinyin is still written as 3rd. You must mentally convert it back.
Reference: This works similarly to the "Bu" tone change. See our note in the Ways to Say No Guide.
Rule 2: The "Half-Third" Tone (3 + Any Other)
This is the rule textbooks often bury, but it is actually the most common usage.
The Law: When a 3rd Tone is followed by any other tone (1st, 2nd, 4th, or Neutral), it becomes a "Half-Third."
What is a Half-Third? You only pronounce the FALL (the low dip). You delete the rise.
- Full 3rd: Drop Low + Rise High.
- Half 3rd: Drop Low. Stop. (Next syllable).
Your voice stays low and creaky, essentially creating a "Low Flat" tone.
Examples by Combination:
- 3rd + 1st:
- 老师 (Lǎo Shī): Your voice drops low for Lao, then immediately jumps high for Shi. You do not rise on Lao.
- Words: 北京 (Běijīng), 喜欢 (Xǐhuan - neutral ending often triggers this too).
- 3rd + 2nd:
- 美国 (Měi Guó): Drop low for Mei, then rise for Guo.
- 3rd + 4th:
- 跑步 (Pǎo Bù): Drop low for Pao, then punch down for Bu.
Pro Tip: If you rise on the first syllable in these combinations, you will sound like you are "singing" rather than speaking.
Rule 3: The Triple Stack (3 + 3 + 3)
What happens if you have a phrase like "I very good" (Wǒ hěn hǎo)? Three 3rd tones in a row?
The change depends on Grammatical Grouping (how the words connect logically).
Scenario A: [2 + 1] Grouping (Common Adverbs)
Usually, the adverb modifies the adjective closer to the end. The sentence breaks into Subject + [Adverb+Adjective].
- Ex: 我 (Wǒ) + [很好 (Hěn hǎo)].
- Logic: Focus on the last pair first. Hen Hao follows Rule 1 (2nd+3rd). Now "Wo" is followed by a 2nd tone... so "Wo" becomes a "Half-Third" (Rule 2).
- Result: Wǒ (Half) + Hén (2nd) + Hǎo (3rd).
Scenario B: [1 + 2] Grouping (Verb + Noun)
What about "Buy Fruit" (Mǎi Shuǐ Guǒ)?
- Ex: [买 (Mǎi)] + [水果 (Shuǐ guǒ)].
- Logic: "Fruit" is one unbreakable noun unit. So "Shuǐ" changes to 2nd tone (because of "Guǒ").
- Intermediate step: Mǎi + [Shuí Guǒ].
- Final step: Now "Mǎi" is before a 2nd tone. It becomes "Half-Third."
- Result: Mǎi (Half) + Shuí (2nd) + Guǒ (3rd).
How to Practice This for HSK Exams
Knowing the theory is one thing; passing the exam is another.
1. The Shadowing Method
Find audio of a simple dialogue. Listen only to the pitch. Don't look at the text. Try to hum the melody. You will realize how flat/low most 3rd tones actually are. Check our HSK Pinyin Mastery Guide for audio resources.
2. The "Nod" Trick
When saying a Half-Third tone (e.g., Hao in Hao Chi), physically nod your chin down to your chest and keep it there while saying the word. Do not lift your chin until the next word starts. This trains your voice not to bounce up.
3. Record and Review
Record yourself saying "Wǒ hěn hǎo." If you hear your voice rising three times, you are wrong. It should sound like a roller coaster: Start low (Wo), climb up (Hen), fall and rise (Hao).
Conclusion: Tone Rules are About Flow
Tone changes weren't invented to annoy students. They were invented because the human throat struggles to switch directions too quickly. "Tone Sandhi" smoothes the edges of the language.
When you start applying these rules naturally:
- Your speaking speed increases.
- Your rhythm sounds native.
- You stop panicking when you hear "unwritten" tones on the HSK listening section.
Keep listening, stop rising, and let your voice drop!
Next Step: Once you've mastered the 3rd tone, you need to master the character that changes tones even more often: "Yi" (One) tone change rules.