Tone change rule
The stubborn 不
不 (bù) flips to bú before another falling tone.
Step 1 of 3
不的变调
不 (bù) flips to bú before another falling tone.
bù + 4th tone is spoken as bú + 4th tone
Written
Spoken
不是bù shìbú shì
不要bù yàobú yào
不对bù duìbú duì
不去bù qùbú qù
不忙bù mángbù máng
Tap a word, hear it happen
不是bú shì
不要bú yào
不对bú duì
不去bú qù
不忙bù máng
Tap anywhere for the next step
Written
Spoken
bù + 4th tone is spoken as bú + 4th tone
不 is normally a falling tone. But two falls in a row sound like slamming two doors, so before another fourth tone, 不 bounces up instead. Before anything else it stays its stubborn falling self.
Some books print the change, some don't. We print bù everywhere and trust your ears to bounce it, exactly like native speakers learned to.
Words you already know, doing it
不是bù shìbú shìis not
不要bù yàobú yàodon't
不对bù duìbú duìnot right
不去bù qùbú qùnot going
不忙bù mángbù mángnot busy (no change: máng is 2nd tone)
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