The document discusses the differences between using "will" and "be going to" to talk about the future in English. While the two forms can sometimes be used interchangeably, they often express different meanings. "Be going to" refers to a plan or intention, indicating something that has already been planned to happen. "Will" refers to predictions, voluntary actions, or promises about the future, and is used when giving information about an uncertain future event or offering to do something for someone. The document provides examples of how to use each form correctly in sentences.