Definition
to abruptly start doing something
突然开始
She broke into song unexpectedly, surprising everyone.
她突然开始唱歌，让每个人都感到惊讶。
In the meeting, he broke into a discussion about the next project.
在会议中，他突然开始讨论下一个项目。
In the emergency, he broke into first aid without hesitation.
在紧急情况下，他毫不犹豫地开始进行急救。