go off
Go off (phrasal verb) means to speak or act with sudden intense energy — either ranting angrily or performing brilliantly. Which one is meant depends entirely on tone. Example: “Don't mention the parking situation or she'll go off for twenty minutes.”
How to use go off
Learner’s notesIn plain EnglishTo explode or sound off, or to suddenly let loose in speech or performance.
The praise sense ('go off' meaning to excel, and the exclamation 'go off!') is young, informal and spoken.
Go off on someone always means to shout at them. Go off with no object is ambiguous between anger and excellence, so listen for tone.
Fill the gap
Can you complete this real example?
Don't mention the parking situation or she'll _____ for twenty minutes.