The document discusses the future simple tense in English, which is used to talk about predictions and promises in the future. It provides examples of using will/won't with subjects to form affirmative, negative, and interrogative sentences. Signal words that indicate the future simple include tomorrow, next week, etc. Examples are given like "You will live a long and happy life" and "Will I be healthy?". The document also contains exercises asking about underlined parts of sample sentences.