break into (something)
1 : to enter (a house, building, etc.) illegally and especially by using force
Someone tried to break into our house while we were away.
2 : to begin to do or have (something) suddenly
She broke into tears. [=she suddenly began to cry]
The audience broke into applause. [=the audience suddenly began applauding]
His face broke into a smile. [=he suddenly smiled]
The horse broke into a gallop. [=the horse suddenly began to gallop]
She broke into song. [=she suddenly began to sing]
3 : to enter or get started in (something, such as a profession)
I knew her when she was a young actress trying to break into show business.
4 : to interrupt (something)
The network broke into the program with a special news report.