The document discusses various ways to express future time in English using different verb tenses. It explains the difference between "will" and "be going to" when making predictions or talking about plans. Examples are provided to illustrate expressing instant decisions, predictions based on evidence, and promises using will. Be going to is used for future plans and intentions or predictions based on what can be seen now. Other tenses like the present simple and present progressive are also sometimes used with time expressions to talk about future events.