The document discusses two main ways to express the future tense in English - using the modal verb "will" and using the construction "be going to". It provides examples of how to form the affirmative, negative, and interrogative for both the future simple with "will" and the future with "be going to". Key uses of each construction are noted, such as using "will" for predictions, quick decisions, and promises, and using "be going to" for plans and intentions or predictions based on clear signs. Several practice examples are provided to choose between using "will" or "be going to".