Tone Change Rules for the Chinese Word 不 (bù)

When starting to learn Chinese, you should start out by mastering pinyin and the tones so you have a solid foundation for pronunciation. 

Trust me, you'll want to focus on this right at the start - it's REALLY hard to go back and try to learn the correct tones after you've acquired a ton of vocabulary!

After learning pinyin and tones, you'll start learning words. One of the first few words you’ll learn in Chinese is 一 (yī), the one-stroke Chinese character, meaning... well, “one”. Another one you’ll soon learn is 不 (bù), which means “no” or “not”. Simple enough, right?

 
Well, as you’ll learn in our Beginner Conversational Course, 一 (yī) and 不 (bù) are tone-changing characters that you should pay special attention to.
 

There are four tones in Chinese, and technically a fifth tone: the first tone (high/flat), the second tone (rising), third tone (low/flat) and fourth tone (falling), and the fifth “neutral” tone (toneless tone).

*** If you're just getting started learning tones, or have struggled with tones in the past, stop right here and watch this live hangout where Yangyang teaches you how to master these tones: 

 
Now, in colloquial Chinese the character 不 (bù) can be pronounced as the fourth, second, and on occasion, the neutral tone. We’ll address the tone changes for 一 (yī) in a separate post.
 
We’ve had many students that have come to us asking about the tone changes for these characters, so we wanted to dedicate this post specifically to address the tone changes of 不 (bù), and give everyone the lowdown on the tone changing rules.

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#1: Fourth Tone (bù)

The rule is that 不 (bù) itself is the fourth tone, and in “normal” situations it will be spoken as the fourth tone. Let’s check out a few examples:

 
• 不行 (bù xíng) - to not work/to not be OK
• 不喜欢 (bù xǐ huan) - to not like
• 不吃 (bù chī) - to not eat

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#2: Second Tone (bú)

The only time that 不 (bù) changes from the fourth tone to the second tone is when it is followed by another fourth tone character - 不 (bù) will then change to the second tone. Let’s see a few common examples:
 
• 不会 (bú huì) - will not
• 不要 (bú yào) - to not want
• 不是 (bú shì) - to not be

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#3: Neutral Tone (bu)

不 (bù) can technically also be spoken as neutral tone when used in potential complements, the “verb-not-verb” structure, and some set phrases with 不 (bù) in the middle. Some common examples are: 
 

Potential complements:

• 吃不完 (chī bu wán) - cannot finish eating
• 听不懂 (tīng bu dǒng) - cannot understand (by hearing)
• 做不了 (zuò bu liǎo) - cannot do 
• 学不会 (xué bu huì) - cannot learn
 

Verb-not-verb structure:

• ...是不是... (shì bu shì) - is/are ___ or not
• ...要不要... (yào bu yào) - want/wants ___ or not
• ...行不行... (xíng bu xíng) - is ___ OK or not
 
Set phrases:

• 对不起 (duì bu qǐ) - I'm sorry

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This concludes the tone changing rules that you should pay attention to for 不 (bù)! These changes can be a bit tough! Our advice is to try to focus on the most common changes - like the 2nd and 4th tone rule, which is pretty straightforward.

The more practice you get with hearing people use these tone changes in conversations, and speaking them yourself in some common and set phrases, the more naturally you’ll make the changes without even thinking about it!

If you're not already studying Mandarin with us, we hope you'll check out our Beginner Conversational Course! You can check out the first 20 lessons for free to see how our program works and decide if you want to take the full course. 

You've got nothing to lose, so start now with Lesson 1!

If you're not a beginner, you can also try the first units of our Intermediate and Upper Intermediate conversational courses , or our Chinese character courses for free. See how we can help you take your Chinese to the next level!

Let us know if you have any questions in the comments below!