Elementary | Tone Rule: Changes for 'bu'

While the writer attempts to interject occasional humor into
these intros, he knows there's nothing funny about the word ‘bu’,
especially when you factor in the rules involved. Sorry, you
don't know the rules? Oh, you'll thank us for this podcast that
takes away the mystery of the changeable ‘bu’ in Mandarin
Chinese, then. Episode link: https://www.chinesepod.com/0453