The document discusses the use of "no sooner...than", "hardly...when", and "as soon as" to indicate that a second event occurs immediately after a first event. It provides examples of sentences using these structures in both past and future tenses. The document also notes that "no sooner" introduces the first event, "did" can be used instead of "had", and "when" and "before" are not used with "no sooner...than". It explains the position and tenses used with "as soon as" in more detail.